Sinclair User Magazine 1984 Annual

1984

TOP ADVICE FOR ZX OWNERS.

Buyers' guide to best software and hardware.

Sixteen pages of superb programs.

1983 REVISITED

Choosing which game to buy from the mountain available is a difficult job,

especially when everyone claims to produce the best on the market. But how can

you tell the best from the rest?. To help you decide, read on. . . .

What the

real critics say. . . .

Very rarely have
software titles produced
such universal acclaim
as "Halls of the Things'

and 'The Dungeon

Master'. Now, with three

brand new programs,

Crystal continues to set

the standard of software

excellence. The

difference is obvious -

the choice is yours:

The Best or The Best.

JTV '■ ***

THE DUNGEON MASTER

Lei your Spectrum be your guide in a totally new
dimension in adventures tn the true spirit of
traditional role playing games whe re YQ L) des Ig n
the scenario.

"I have been a Dungeons and Dragons fan for
several years—The package provides excellent
entertainment lor all fans of the cults and should
prove a good introduction to the game".

....Sinclair User.

aid quality. Definaiely well worth obtaining".

,...ZX Computing.

Z X S pec t ru m 46 K E 7 . SO

Written by Graham Stafford.

HALLS OF THE THINGS

A stunning murtMevei maze 'arcade -adventure".
"Excellent and dangerously addictive - could
change the Spectrum games scene
overnight". . ..Sinclair User.

"Spectacular ■ One of the beat games I've seen,
finely balanced between simplicity and
addictiveness - superb graphics and colour - I
CANT RECOMMEND IT HIGHLY ENOUGH'"

...Popular Computing Weakly.
ZX Spec tru m 48 K £7 So

Written by Neil Mortershead, Simon Brattel and

Martin Horsley-

INVASION OF THE
BODY SNATCHAS!

At last 1 a version as fas! and furious and as
IrustTatingry addictive as the arcade original.
Landers, Mutants, Bombers, Pods, Swarmersand
much much more combine to produce the

ultimate space game!

ZX Spectrum 48K £6. SO

Wrihen by Simon Bra it el and Neil Mottershead

Please Send SAE for our latest catalogue and
details of our forthcoming software.
Catalogue FREE with every order. P4P included
Please add £0,50 per item for overseas orders
Please make cheques/PQ's payable to;

CRYSTAL COMPUTING A

Dept SU 1 1

2 ASHTON WAY

EAST HERRINQTON

SUNDERLAND SR3 3RX

<

^ V #U'

Please Supply:

invasion of the Body Snaichas U

Rommel's Revenge D The Island CI

Hatls of the Things □ The Dungeon Master □

Catalogue (please enclose SAE Bin. * 9ln.) LJ

I enclose cheque/PO lor . , . . , , . .

NAME

ADD RESS ,,,,,.,. ....,,..,..

ROMMEL'S REVENGE

A brilliant interpretation of the moal visually
stunning arcade game of all time. Superb h»gh
resolution 3D graphics with full perspective plus

a host of new and exciting tea lures make
Rommel's Revenge the mosi spectacular game
ever produced for your Spectrum'

ZX Spectrum 48 K £6,50

Written by Martin Horeley.

DEALERS! For details of our excellent ' j

dealer discounts {Including export) ,:

ring Cririt Clarke on 081 -205 6803. r|

PROGRAMMERS! Written any good \

software? send It lo us for evaluation and *

details of our excellent royalty scheme. t

X

SUA

Sinclair

>

* Compete ZX CPU*"***

Managing editor
Nigel Clark

Deputy editor

Nicole Segre

Consultant editor

Mite Johnston

Managing production editor

Harold Mayes MBE

Snftware editor

John flilhen

Program reviewer
Rebecca Ferguson.

Illustrator/ designer

Priori King

Gruup advertisement manager

John Ross

Sales executive

Annette Burrows

Production assistant

Yitv.i Epjinnnondou

Managing director

Terry Cart bright

Chairman
Richard Heasc

Sinclair User Annual U pubLlihed

by ECC Publications Ltd- It is in

no way connected with Sinclair

Research Lid.

Telephone

All departments

01-359 3525

If yau would like to contribute to

any of the Sinclair User group of

publications, please send programs.

jrndesor ideas for hardware

project* to:

Sinclair User and Programs,

ECC Publications,

1 96-20Q Balls Pond,

London N I 4AQ

Programs should be on cassette and

amides should be typed, We CHUMM

undertake to return them unless a

stamped-addressed envelope is

included.

We pay £10 for the copyright ed

each program published and £50

per 1 ,000 words for each ankle

U'.-.'J

© Copyright 1983

Sinclair User

ISSN No 0262-5458

Primed and typeset by

Cradlcy Print PLC,

Warley,

West Midlands

Distributed by

Spotlight Magazine Distribution Ltd,

I Benwell Road,

Holloway,

London N7

01-607 6411

CONTENTS

7 NEWS

A review of the important events in 1983 including the launch of the Microdrive
and a knighthood for Sir Clive Sinclair.

11 SOFTWARE SCENE

The best guide to all that is available for Ihe Sinclair machines.

39 HARDWARE WORLD

Stephen Adams gives his views on the peripherals which are now available.

45 PROGRAMMING

A complete series on how to write in Basic.

61 INSIDE SINCLAIR

Behind the scenes at Sinclair Research.

73 FUTUROLOGY

Looking into the future and seeing a large demand for the microcomputer.

81 BOOKS

John Gilbert investigates publishing in 1983,

85 PROGRAM PRINTOUT

Sixteen pages of the best programs of the last year, plus two more.

105 HELPLINE

Andrew Hewson and the pick of his regular columns.

117 USER OF THE MONTH

Meet the people who find unusual uses for their machines.

131 MEMORY

Find the best way to expand your RAM.

SINCLAIR USER Annual 1984

T AROUND THE CORNER, A NEW

ZX COMPENDIUM

MOVIE MOGUL tUXGMth

wmm

-!*%#>*-

BLACK CRY5TAI

Thr (Ijwn sis program advmlure game lor ihe 4UK Spectrum and 16K ZX-BT
computer*. Nu Milrw jrt lolWtion is complete without it.

"BLACK ( 'KYI SEAL is jn excellent graphics adventure and a well thought oul
package" (Sinclair Uhi, April 'Wl-

"Bl ACK CRYSI Al Kj% impressed m* by its sheer quantity and generally high

talily ol presentation. I am afraid I have become an addict" iHurrw Computing
.'eekly. April '«,<'
SPECTRUM 4HK 1S0K ui program in six parts . . . only £7.50
ZX-BI 1«K over IODIC of program in scvm part* . , , only £7,50
Why pay more lor leu oi an adventure?

THE ADVENTURES Ol Si HFRNAHl)

An tucking, fast moving, machine code, arcade game where yrai guide youf
Irepid St, Bernard (hrnugh ihc p*rils ol ihr ky w**l*l*nds tu rescue hi* Mistrrs*
»m the dutches or the abominable snowman. 4BK Spectrum ES.9S.

THE CKYPT

written K Stephen Krnlim

Prrparr >i>urs*!( ior the many chjllen^ that shall confront you when you dare

ratter THE CRYPT

You will batik? with giant scorpion* Hvll <pjwr. Cr alters, Pcis-Nrgs -old if you
are unlucky enough — the Dark Cyclops in this arcade si vlr aduritture.
flVllflluiT now for thr *8K Spectrum (ff U,«

ZX-8I CUMPE INDIUM

.tiiri Intruder. Wumpu* Adventure, Numerology, Hangman, Hiftojlyphm

ovie Mogul.

The ideal software package for all le>K ZX-fll owner*. Si* major programme* on
Avn cassettes inr only I< J ,5C-

"Alien Intruder Hieroglyphics — Bfllh programs make goad uu of graphics and
words, to make a very entertaining package." I Sinclair Usur, Aug '021

■ Alien Hler<i K !vphk<. IVumpn Movir A varied mis, Irom CarneJt, ill Unit-
ing imaginative nsfjonwi and graph ks and all id thrm good games for all ages
i Hieroglyph it- is particularly good for children'. " (Popular ( urn puling Weekly.
Aug '831

*1* ^ ,

S1ARFORCEONE

I .ike (in I he robm guardian* of thr centra] computer in a superbly stylised lh>
dimensional battle game. Wti Spriliujm 115.95

hoc. MAC"

THE DEVIL RIDES JN

1 uttered thr Us) innnljtluin as the clock struck thirteen. All lell silent t-sirpt |or
j faint rustling in the corner. From out nf thr shadows I hey came, all Hell's hiry
against me but I w« not delencelrss until the Angel Ol Death., astride * winged
horse fuined the battle. Avoiding hi* bolts <if hell fine, I took careful aim. My
chances were slim, but if my luck held . . . 48-K Sparine

I Fast moving, machine code, all action, Arcade game)

COMING SOON

"""WRATH CM MACK I

The rrret h&m hi* twn drrtrnvwl- Th* Black CrytJal ui nWolh ha* bwn tranUhed
The alliance of tvit >m» been ikuatcd by th* *rmJei of Lord Feudal. So end* the
Tti-J Ajje. Now w* mute you <t> writ* your name in tb* hftfory of ihr !\njrth Age
Third Continent,
ou "ill mm friend* and .MRim. old and new. in ihc Ionic jwaurd vqurl Id
k*nk [>nna*nn Uabaj W^i rwotutkm graphic* ar»d combining the t»ni qptttaai
'Slack Cr\»!al *n<l Vofcank Dune-eon '. w» will allow von to bfCOf** part p|
Lhi* tale l»# tevenajr,

Th* Wrath Of Magra come* a* lhr**, HK program* <m ca***tte. Nwd with
l—irnfllim manual jrd boot detailing th* hi*tory ol the Third Co«(«n« and th*
many spelU vou Mil br .J*ifiS ihroughtHit the liJfne.

ISOTf: The Wrath OJ MiRr* it a complete adientu**-
Vokxnit Dunneon or Biick Cryrtal to pin i(

"n... liable thriwish mo»l #sw>d computer itores or dl*«t from;

Camell St,ltv»are Ltd, North lV,yUnd* Indmtnal Lslate, MoWey Road,

l>al<*tL Can! ail u* ior your rt*af#*t wholesaler,

rrry KTI2 JPL.

CARNELL SOFTWARE LTD

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KELWOOD COMPUTER CASES

W#' Downs Row. Moorgate, Rotherham Tel: (0709) 63242

SINCLAIR USER Annual 1984

-

i

News

*

^^^^ ^w

r--* - "* ^

k ^

^^H

The last year has been another eventful one

in the Sinclair market. The arrival of the

long-awaited Microdrive and a knighthood

for Clive Sinclair are only two of the items

we cover in this assessment of the

developments of the 12 months.

SINCLAIR USER Annual 1X4

Mike Johnston reports on last year

Market reaches
critical mass

IF YOU GATHER sufficient radio-
active dement together., at a Certain
point it reaches a critical mass and a
chain reaction follows. Something simi-
lar seems to have happened with the
density of home computers in the popu-
lar ion early last year. Suddenly every-
one seemed to want a home computer.

Computing was scarcely a minority
interest even before that, with an esti-
mated half-million home micros in use
in the U.K, in 1982 but in 1983 it
caught the public imagination. Com-
puting became news.

The Sunday newspaper colour sup-
plements contained features on comput-
ers, the daily papers started computer
columns, young programmers were
hailed as the new pop stars and, perhaps
most fittingly, Clive Sinclair, the man
who invented the home micro, received
a knighthood.

While micros in general began to
receive increased media coverage, Sir
Clive and his company were rarely out

of the news. In December, 1982 a strike
at one of the Sinclair subcontracting
plants, Timex in Scotland, made
national headlines. In January the sale
of 10 percent of the company to City
investors for £12 million and the news
that Sinclair Research was worth £130
million practically guaranteed more
coverage.

In March Sir Clive was named
Young Businessman of the Year by The
Guardian. In April there were more
industrial relations problems at Timex
and the development of the flat -screen
TV project was affected. The Spectrum
price reduction in May made headlines
as the first colour computer for less than
£100 — the 1GK version sold for £99 —
and the June announcement in the
Queen's Birthday Honours of a knight-
hood for Sir Clive made even bigger
headlines.

Later [hat month the Sinclair plan for
a high-technology think-tank again at-
tracted the national press. In August,

the final release of the Microdrive was
just a little of an anti-climax — after
'coming shortly* for 18 months — but
that was capped in September by the
unveiling of the flat screen TV, first
announced even earlier.

Sales of the Spectrum soared during
the period, perhaps helped by all the
publicity, from 60,000 in November,
1982 to more than half-am ill ion by
August, The 2X-81 may have done less
well, although no figures have been
released, despite the considerable price
reductions — down to £40 in May and
again down, including 16K, to £45 in
August. Sinclair is continuing to sup-
port the machine bui the W H Smith
announcement that it would not be
stocking any new titles for the ZX-81 is
perhaps ominous.

Sinclair has not had the field entirely
alone, as he did in the early days, and
the less-than-£200 market has become
increasingly crowded in the last 12
monthSj with some fierce price-cutting
taking place as companies jockeyed Tor a
place.

The Vic- 20 fell from more than £200
to around £140 in some shops before
last Christmas and other companies fol-
lowed suit — Texas, Atari, Lynx, Drag-
on — either by reducing the price or
offering a machine as part of a package
including software or other hardware.

After Sinclair reductions in the price
of the Spectrum in May, there was a
further round of cost -cut ting from other
manufacturers. All of which has been
good news for the consumer, who now
has a much wider choice at lower prices.
It has not been such good news for some
companies foroed to reduce their profit
margins to compete with the Spectrum
without the advantages large-scale pro-
duction brings.

Despite the competition, the Spec-
trum has managed to maintain a healthy
lead over its rivals and continues to top
the best-selling hardware charts. By the
end of March, the company was report-
ed to have doubled its turnover from
£27 million to £54 million and made a
profit of £14 million before tax,

In the U.S., where competition has
been even suffer, a number of large
companies, including Texas Instru-
ments, x^tari and Mattel (Aquarius) had
substantial losses, Timex, which makes
Sinclair lookalikes, has not done too
well either 3 despite a promising start.
The TS2000 (Spectrum + ) was due for
release early in the year but was de-
layed, then re-designed to meet the
competition. Timex was forced to make
heavy discounts on the TS 1000 (ZX-81)
to boost flagging sales.

SINCIJVJR USER Annual 19&4

-

PlavwithaGriffin

; Sothey/takeschoolintheirstride *

*

A m.

*

W * si.

lour children are using a computer at school far
more often than you think

Computers make learning an absorbing game
and retasn a child's interest and participation

Cnffin Software have selected and adapted for
home use. a senes of Griffin educational software
tides already used in schools.

The first six titles suitable for 4 to 6 year olds,
are available now.

If you have a ZX Spectrum 48K or a BBC
Model B mif roco mpu c K at home.you ca n so easily
keep up the school's good work And the beamy of
it is. the child sees it as a game?

Wordspell helps with
spelling: Tablesums unravels
the mysteries of tables;
Fairshare uses Ollie the
Octopus to make sense of
division: Mumberfun makes
addition and subtraction
easy; Wordgames helps with
spelling and expands vocabulary: and withCetset
a child is helped with counting.

All good fun!

Griffin Software titles are at W H Smith. Boots
and other computer shops everywhere.

Orrly .(/Speech to suit tht£X6pfctnjm 48K Only £9 9i nvi 'i .'" v mi ' td a

GRIFFIN
SOFTWARE

- tfs an education.

One advantage the Spectrum has con-
tinued to enjoy is a very large and
sophisticated software base, Many com-
panies which produced software for the
ZX-81 have found it easy to make the
transition to Spectrum software. Other
companies from the record and publish-
ing world — Thorn- EMI, CBS, Virgin

— attracted by the large potential mar-
ket, have also joined the contest.

The number of new software com-
panies, large and small, to have joined
the Sinclair industry in the year is
astonishing. They are almost as numer-
ous as the new computer magazines —
two new weeklies and innumerable
monthlies which appeared during the
year, A feature of the last year has been
the movement into software. Compan-
ies once specialising in hardware, like
Quicksilva, dK'Tronics and Kempston,
have begun to market programs. Quick-
silva ceased production of hardware en-
tirely.

Software has become increasingly big
business with the one-man program-
mer/entrepreneur giving way to the
publishing software house which com-
missions programs from freelance pro-
grammers or employs full-time software
producers. In recent months computer
magazines have been full of advertise-
ments for programmers and/or pro-
grams, preferably in machine code.

A number of companies now have
large minicomputers which behave like
Spectrums — or Orics or BBC machines

— but which offer many additional
facilities for developing software. Psion,
which had a £5 million turnover last
year, produced Flight Simulator
using such a machine; Melbourne
House developed The Hobbit in that
way; and Ultimate devised PSST.

More recently, Virgin Games de-
clared its intention to use such a system
in preference to commissioning pro-
grams. While it is still possible* no
doubt, for someone to run a part-time
company from a kitchen table, those
developments make it more difficult
because of the users* demands for well-
finished programs and the costs now
involved in marketing.

It is an indication of the size and
popularity of the computer market thy;
it is beginning to attract crime. Three
thousand Spectrums, later recovered,
were stolen from Prism Microproducts,
the Sinclair retail distributor, in June, It
has also become profitable to pirate and
mass-produce popular games tapes
which are then passed -off as originals
from the major software houses.

Another issue which has enraged
some software companies is the one of

software libraries. In March, Quicksilva
applied for an injunction against a com-
pany it claimed was effectively lending
Quicksilva programs, which might easi-
ly be copied.

It is an indication of the seriousness
of software companies and the large
amounts of money involved in fraud
that two organisations have been set up,
The Computer Traders' Association in
February and the Guild of Software
Houses, Both claim to be seeking
methods of protecting the customer and
policing the industry,

Methods of distribution have
changed, too, and have become better-
organised. Mail order is still popular
but many users prefer to see in advance
what they are buying, without having to
wait. More and more s software is being
distributed through wholesale and retail

'Companies once

specialising in

hardware have begun

to market programs*

outlets. Prism Microproducts has
reached an agreement with an electrical
retail chain to establish software dis-
plays in the shops, which will be re-
stocked regularly by Prism. It is hoped
to extend the system to other retailers.
Prism also hopes to introduce electronic
distribution of software via a terminal
held by the retailer.

Another new development for the
distribution of software appeared this

year, after two false starts, Micronet
800 produced an adaptor which allows
the Spectrum to be linked via a tele-
phone line to Prestel and to the Mi-
cronet programs and information on
micros. It also opens the possibility for
Sinclair users to contact each other via
the system.

Star item this year, though, was the
fabled Microdrive and Interface One,
which finally surfaced in August after
numerous false alarms. It was almost
bound to be little disappointing, consid-
ering the length of time we had to
imagine how wonderful it would be.
Having said that., there is little doubt
that it will be reasonably high on the
shopping lists of most Sinclair users for
add-ons; 85K of program loading in a
matter of seconds must be worth wait-
ing for and for most of us the wait is
like I y to be some time.

The only serious reservation is the
price of the cartridges. The interface
and networking look ideal for use in
schools and may go some way to up^ci
ting the near monopoly of BBC ma-
chines. That was one area where the
Spectrum has not been too successful so
far this year.

The other major piece of hardware
from Sinclair appeared at the Personal
Computer World Show. The interlace
Two seems to be designed specially for
those who can admit that they did not
really buy a computer to work out
quadratic equations at all. A joystick
controller with plug-in ROM car-
tridges, it allows instant access to your
favourite games programs with a mini-
mum of fuss. The Interface is priced
very reasonably at around £20 but the
games cartridges are a lit tie more ex-
pensive at around £15 each.

10

SJNC1JUR USER Annua! 1984

Software Scene

An important part of Sinclair User is the

review of the latest software. Our writers

give their opinions on the best available for

both the Spectrum and the ZX-81.

SINCLAIR USER Anmai 1984

11

John Gilbert's overview

Development rate
is 'astonishing 5

THIS YEAR the software indus-
try has been very fortunate in
having more rises than falls,
although in most cases that is due to
luck and the market situation rather
than good software. The rate of devel-
opment and achievement by some soft-
ware houses has been astonishing at
times. In the adventure sector The
Hobbit swept the board for accolades.
Arcade software Time Gate, 3D Cora-
bat Zone and now Maziacs, have
stood out from a bewildering array of
space and maze games.

The Hobbit sent thousands of 48K
Spectrum owners mad and floored most
critics, who could not get enough of it.
Many critics thought, when it was first
released, that there would be many
imitations. The critics were wrong as
there are some companies trying to
equal the game but no-one has managed
to capture the same atmosphere of mad-
ness.

As with adventure games, arcade soft-
ware has reached a peak. The year
started with John Hoi I is* Time Gate
from Quicksilva which showed what
could be done with the graphics capabil-
ity ofthe Spectrum. Particular attention
was paid to the three-dimensional
effects used in the program and, as an
early effort, Time Gate was stunning.

Another game which shows-olT the
graphics of the Spectrum is Halls of
the Things from Crystal Computing.
It stretches the Spectrum graphics
facilities to the limit and provides an
incredible chase round a multi- level
maze, populated by strange and deadly
creatures.

The game has proved popular with
many people although, for some reason,
retailers seem reluctant to stock it.
From the moment it is LOADed, Halls
ofthe Things displays signs of technical
excellence, [f you watch closely you will
notice something unusual happening
when the title screen enters the com-
puter. The display does not appear in
blocks on the screen. It appears to move
vertically straight down until it hits the
last line of main screen and then the
game begins. There is no wait between
the LOADing of the initial display and
the game.

It is surprising that no manufacturers
of software have tried to duplicate the

Unfortunately the business and edu-
cation market is not much further along
the road than it was at the start of 1983.
It is too soon to visualise what compan-
ies are likely to do with the Microdrive
but manufacturers already in the busi-
ness have made a good, if slow, start.

Most ofthe products produced in the
last year have been for the home finance
market and. include Finance Manager
from OCP and Business Accounts
from Wilsdcn Computer Services.

efforts of Crystal, although one game, Little has been produced but the pro-

Maziacs from dK'Tronics, is close to it
It also relies on speed and graphics for
its appeal, A good deal of thought obvi-
ously went into the visual presentation
of Maziacs and because of that it is
attractive package

an

ducts available are of good quality.

The main contributor to the small
business market is Hilderbay, which
still produces a Stock Control Pro-
gram and PaiyroII program for the
Spectrum and ZX-81. Hilderbay is an

A new type of game to emerge in exception to the rule, as it also produces

1983 was the graphics adventure. Until
a short time ago most adventure games
used text only to describe the locations
which could be visited by the 'player.
The Artie adventures provide good
examples of this type of game.

The new class of adventure uses
either fulfscreen to illustrate locations
or split-screen with text at the bottom
and a picture ofthe currenr location at
the top.

The first graphics adventure was

software for other more expensive com-
puters, such as the Apple II, and so has
the experience to produce the proper
type of program.

Another company to edge its way
into the small business sector is Kemp.
It has provided businessmen with three
very usable programs— Purchase Led-
ger, Stock Control and Stock Led*
ger. Unfortunately they are available-
only for the 48K Spectrum.

No doubt programs of this kind will
Pimania, although it differs slightly soon have Microdrive upgrades but un-

from the strict definition ofthe category
because the locations are not displayed
using graphics. The animated graphics
which are used^ including the Pi-man
singing, give clues to the solution to the
puzzles which are posed in the text, or
an admonition to the player who is not
doing very well. There has been unmis-
takable reaction from players— you
either love it or you hate it.

Apart from Pimania, the first graph-
ics adventure for Sinclair machines was
The Black Crystal from Carncll Soft-
ware, It provided the basis for several
similar games where the locations were
put on to a screen map and the player
moved a marker around it.

The next development of this type of
format was provided by Doric Com-
puter Services which produced a Spec-
trum version of The Oracle's Cave.
The bottom of the display is taken-up
with a description of the cave system
which you are in and the top contains a
silhouette picture of the cave and your
player-figure in the cavern.

That figure will walk and climb,
depending on what you are asking it to
d o f and the whole scene is very lifelike.
The graphics are smooth, startling and
exciting. They show the way for the
development of the graphics adventure
in the next year.

til then they are of somewhat limited
use for anything but small businesses.

There is little worth noting in the
education field this year, except for the
MEP programs from Sinclair Research,
Sinclair took the unusual step of adver-
tising the programs as ones which will
be used in schools and can be bought Tor
home use.

One company moving to the fore this
year, not because it retains any real I v

12

SJ NCI AIR USER Annual 1984

outstanding programmers but because
of the simple brilliance of the teaching
technique which is used in the pro-
grams, is Widget Software. It has pro-
duced several educational programs but
one of the most exceptional is Path-
finder. The cassette contains four
games based on different mazes. The
idea is to learn as you play — an import-
ant lesson to be learned by all edu-
cational manufacturers.

Young people learn more easily by
playing games, so Widget has concen-
trated on combining educational con-
cepts with play. Although the programs
are written in Basic, they perform the

to games and utilities as soon as the
machine is switched on.

Next year there should also be a
radical change in the way software de-
velops and how it is accessed. Software
on Microdrive and on ROM cartridge
are only two new items. The third is
telesoftware which can be accessed from
Micronet 800.

Telesoftware can be accessed from a
central database of programs via tele-
phone line*. The programs are trans-
mitted or downloaded from the database
and can then be listed on the user's
computer. At present the service is
available only for the Spectrum but

'Now that 48K Spectrums are beginning to
filter into schools, children will lose the attrac-
tion for games and begin to treat computers,
and the software which they run, as tools'

dual task of teaching and keeping a
child interested very well.

Education is another area in which
the Microdrive will he useful. It is
possible to store information, graphics
and questions on Microdrive which can
be called up by a teacher or a student.
In that way it will be a valuable tool and
educationalists would be advised to take
advantage of it.

It is too early to see the effects of the
Microdrive, Interface One, or even to
see what impact Interface Two will
have on the Spectrum. Interface Two
will contain a ROM cartridge system
which will allow users to plug in cart-
ridges similar to those used with Atari
machines. That will give instant access

Micronet plans to make it available for
the ZX-81.

Some people regard telesoftware as a
threat to mail order and to cassette
software. Those arguments are not logi-
cal nor will they be pertinent in a few
months. Mail order seems to be dying
and the retail shops, such as W H
Smith, are taking-over the sale of cas-
sette and disc-based programs. Because
of the easy availability of those pro-
grams, cassette software will be with us
for a long time. After all, not everyone
will not want to buy a Micronet adapt-
or. It is rather like saying that every-
body who wants a video will not want to
watch live television.

The Sinclair software scene has
undergone a massive change this year
but that is nothing compared to what
may happen in 1984. Now that 48 K
Spectrums are beginning to filter into
schools, children will lose the attraction
for games which they had initially, and
begin to treat computers as tools which
can be used for a purpose in everyday
life. Demands for games software
should recede slightly and the educa-
tion, and eventually business, market
should benefit from that.

Children will still have an initial
fascination with computers but that
should turn to understanding now that
many schools are geared to computer
science. While 1983 has been a year of
consolidation of the market, in 1984
there will be an expansion of the moves
which have already begun for practical
uses on the Spectrum and still, to some
degree, the ZX-81.

Sinclair
accounts

John Lambert

THE SPECTRUM and ZX-81
have no reputation for being
serious business computers but
they are built around the same central
processing unit as many grander ma-
chines and can perform all the functions
required of a business computer system
by a small — or not so small — business.
The high-quality software necessary for
the purpose is becoming available to
meet the needs of an ever-expanding
market and the recent appearance of the
much-vaunted Microdrive for the Spec-
trum promises to rival some of the
bigger disc-based systems. With the ad-
dition of a full-size printer and inter-
face, your computer can deal with your
accounts > filing system, word process-
ing, business planning and payroll and
produce results of a professional stan-
dard.

To be fair to Sinclair, its machines
were not designed with the business
user in mind but rather to be a low-cost
introduction to computers in the home.
In that it has undoubtedly succeeded
but it imposes certain limitations, the
most noticeable of which are lack of
memory and data storage.

Memory, however, should no longer
be a problem, given the large number of
add-ons on the market, and the Micro-
drive provides quick and easy access to
large amounts of stored data.

The Sinclair keyboards have attract-
ed criticism but again if the user finds
them a ppoblem a number of full-size
keyboards are available. The screen dis-
play can also pose a problem, 32 charac-
ters per line often not being sufficient to
produce the required display, but by
careful programming the software can
either give up to 64 characters or allow
the user to output to a full-size, 80-
column printer. Ultimately using a Sin-
clair machine in business will not be the
same as using a large, dedicated ma-
chine, but different does not necessarily
mean worse.

Accounts programs lie at the heart of
a business system. They give the busi-
ness user a powerful tool in the running
of a business where at the touch of a
button a list of debtors and creditors can
be called-up or even a set of accounts
produced. In that way it is possible to

SINCLAIR USKR Annual 19M

13

keep far greater control over affairs.
Having decided to operate a computer-
ised accounting system, users must first
decide which program to buy.

There, unfortunately, they must
make their choice. There are many on
the market ranging in price from about
£\Q upward? and each will perform in
slightly different fashion. If possible,
the user should take an account to one
of the bigger computer shops to try the
programs or if that is not possible to
contact the software house direct.

Firms such as Transform Ltd or Hes-
tacrest Ltd both supply a range of
programs known technically as a suite
— for both the ZX-81 and Spectrum —
and Gemini, which produces a suite for
the Spectrum, will be ready to guide the
prospective buyer through the maze of
software and hardware available.

Having bought your program you
should not have to spend hours learning
an alien subject. Your computer pro-
gram will take you step by step through
each stage by a series of prompts and
menu selections. There are two import-
am things to remember. First, garbage
in, garbage out — i.e., if you enter
incorrect data, do not expect the com-
puter to read your mind. That is how
you can send bills for £0.00. Second,
always make a back-up copy of data
entered. Normally that is done by the
father-and-son method, where two tapes
are used alternately so that, should
there be a power cut or some other
disaster, you will always have an up-to-
date record of your data.

Computer-generated invoices are al-
ways impressive and generally less time-
consuming to produce. Take for
example, the invoicing program from
Transform Ltd. Initially you would en-
ter a list of your clients' names and
addresses, together with your own, and
then whenever you wished to send an
invoice/credit note you would have to
enter only the first three letters of the
name for the computer to find it.

The computer also takes care of all
the calculations of VAT, pricing and
the various Forms of discount, i.e., trade
settlement and the like. Having arrived
at the total, it will give you the option of
priming as many copies of the invoice
as you wish, even pausing to allow you
to change the paper in the printer when
necessary.

At any time you can print a list of
outstanding invoices or print your state-
ments. Additionally the program will
even print-out your address labels but
that facility will be examined later.

Purchase/sales ledger are the main
accounting books of any business and as

such are catered for by a number of
software houses, notably Hestacrest,
Transform, Kemp and Gemini. The
Cash Book program by Gemini for the
48K Spectrum offers the user some 88
nominal accounts, split evenly between
profit and loss and balance sheet which
cover all the usual business items, plus
memo accounts. It also has the option to
make journal entries.

VAT naturally is catered for and the
program will provide the figures neces-
sary to complete your returns. The
batch system of data entry is used — the
purchases or sales are put into batches
and the computer checks the batch total
against the total individual entries to
ensure correct entry. The data files
created can be used by the Gemini Final
Accounts program to produce a very
impressive set of accounts.

Hestacrest also supplies programs for
the ZX-81 and Spectrum which supply
a set of accounts for either the sole
trader or a limited company.

For stock control, there is a wide
choice of programs from such firms as
Gemini, Kemp — which also produces
a Stock Ledger — Transform, Hesta-
crest and Hilderbay. Using the larger

'Databases is an area
where people expect
the computer to rule"

Spectrum, Stock Control from Hilder-
bay can handle approximately 1,300
lines with details of name, stock level,
re-order level, type and supplier code,
unit value, total value and a text de-
scription. There is also the facility to
print-out a list of all items which are
below the re-order level or even to print
a total stock value.

Databases is an area where people
expect the computer to rule. It is able to
store large amounts of data and to man-
ipulate it in any way you wish, whether
you want to control stock, store names
and addresses or to keep track of stocks
and shares.

Of those on the market, probably the
best -known are those from Campbell
Systems, namely The Fast One for the
ZX-81 and Masterfile for the Spectrum
16K or 48K. They must be the fastest
and most comprehensive available for
the Sinclairs. By using dynamic fields
— that is each record and each item in
each record can be of different length —
maximum use is made of the memory
and by writing almost entirely in ma-

chine code you have a very powerful
program.

Its one disadvantage, if it can be so
considered, is its extreme versatility. To
use it to the full, a passing acquaintance
With computers is a great help, which
may deter some would-be purchasers.
To the business user a pre-packaged
stock control or address program may-
prove a better choice.

A dedicated mailing list program can
prove useful to anyone who wishes to
keep a record of clients or perhaps club
members. Address Manager by OCP
can store up to 4<X> names and addresses
for i he purpose and can sort them, it
desired, into categories. Mailing list
programs are also available from Gemi-
ni and Hestacrest,

A bane of an employer's life must
surely be the calculation of income tax,
especially if more than six weekly- pa id
workers are employed. Now, rather
than doing the job of the Government,
you can use your computer. Hilderbay,
among others, offers a payroll program
which it guarantees to be correct; it also
offers a Statutory Sick Pay program.

The purchase of a computer could
well be justified even if it was intended
only to be used for one of the foregoing
programs. There are many other areas
where its calculating ability can be put
to good use. The best -known utility
business program is the spreadsheet
type of program. It can best be de-
scribed as a grid of boxes where each
box can be identified by its row and
column position, with the contents cal-
culated by referring to the relevant cal-
culation for that particular row and
column. By altering the criteria for the
calculation it is easy to see the result of a
what-if? situation. Of the Spreadsheet
type of programs, VisiCalc for the Spec-
trum or ZX-81 from Sinclair are well-
known but others are available from
MiCrol, Myrmidon (ZX-81) and Work-
force (Spectrum).

Critical Path Analysis from Hilder-
bay for both the ZX-81 and Spectrum
allows the user to enter a network of
more than 500 activities, Le., costs,
duration and resources, and the com-
puter will find the critical path,

Optimax from Hilderbay for the ZX-
81 is a linear optimisation program
where up to 75 variables/constraints are
entered and the computer finds the
optimum. For example, if a farmer
wants to optimise cattle feed, by enter-
ing the nutrient value of foodstuffs and
the cost, the computer will determine
the most cost-effective mix.

If your business is such that all time
spent is charged to your clients, as is the

14

SINCLAIR tJSBR AtiHual ti/84

case with accountants* advertising
agents and the like 3 Time Ledger
should prove useful. It can handle up to
17 employees and 200 clients and is
available from Hilderbay for the ZX-81,

Should you need labels printed, Hil-
deibaj can MtppLv a progrsoa tor the
Spectrum 48K to print them. The label
;an have the date and nine calculable
fields of information and a range of
si^es- If necessaryj the company sup-
plies the labels.

Budget, also from Hilderbay for the
ZX-81, will help the business user keep
track of expenses through the year.
Comp-U-Share for the ZX-81 or Spec-
trum 48K allows the user to keep track
of various shares and investments and
can be obtained from Software Work-
shop,

Having produced your figures,
Graph Plot by Gemini will do that, by
means of pie charts, histograms or
graphs. Those graphs aid the user in the
comparison of figures or as a selling
tool. They are available for both the
ZX-S1 and Spectrum.

One of the most frequent uses of a
computer after databases must surely be
word processing, With the addition of a
full-size keyboard a Sinclair computer
can become a very effective word pro-
cessor.

Of The programs available, Tasword
by Tasman Software for the ZX-81 and
Tasword Two for the Spectrum stand
out. Tasword Two offers facilities
which would not be out of place on a
Wang system. With 64 characters to the
line, the ability to justify text and gener-
ally to move it around at will — either as
blocks, lines or single words — and to
be able to replace or alter words in the
middle of a piece of test make it a very
powerful system.

Technical or specialist programs are
an area which show how cost-effective a
Sinclair machine can be. Similar pro-
grams for larger machines cost in the
region of £500 for the software alone
and yet in most cases the program
requires the computer to act only as a
calculator on a set number of variables.
Any one of those programs, therefore ,
represents a remarkable saving, in that
in a big company each engineer could
have his own computer and even in a
smaller one the time saved would pay
for the machine in its first day of use .
One such is Beam scan by G A Rooker
for the ZX-S1 or Spectrum, of which a
full review is given elsewhere in this
section.

It is well-known that a moving dis-
play in a shop window will attract
customers. W H Smith puts it to good

v^^

■^^^^

V * * % % ,

use when it started selling the Spectrum
in its stores by using the Spectrum ro
sell itself. The most recent program
aimed at the display market is Dlan by
Campbell Systems. Using a range of
built-in type Styles, colour commands
and scrolling techniques with a built-in
timer, a display can be built and made
to alternate displays in a set timed
sequence.

What happens to software will de-
pend on the advances in hardware.
Most of the Spectrum business pro-
grams are being updated to take advan-
tage oT the Microdrive, even though its
reliability has yet to be proved. The
new Interface Two with ROM cartridge
slot will also add a new edge.

Perhaps the most important additions
to the range of add-ons are the Micronet
800 adaptor and the RS232 interface
which can be connected easily to a
modem. The possibility of, say, two

'The ZX-81 also has

its place in business

in the future'

computers which cost less than £100
communicating with each other any-
where in the world where there is a
telephone offers untold possibilities.

The ZX-8 1 also has its place in busi-
ness in the future. Fitted with suitable
sensors it must be the cheapest way on
the market to control equipment, from
factory machines to a programmable
office burglar alarm.

Software continues to improve but
the problem is one of communication.
Ten years ago businessmen were
buying £10,000 computers which could
do less than a ZX-81 today. Today the
same businessmen still spend £10,000

on computers when for £5,000 they
could have a complete word processing/
accounting packagej including the price
of the printer. For software writers it is
unfortunately true that business soft-
ware is not profitable on anything but
the smallest scale. Until businessmen
realise that high prices and high-press-
ure salesmanship do not necessarily
mean high quality, business use on
Sinclair machines will remain little
more than a sideline.

USEFUL ADDRESSES

Blindfold Utd. Rydtngs, Callows Green.

Alton, Stoke on Trent,

Campbell Systems. 1 5 Rous Road, Buck
hurst Hill, Essex IG9 6BL Tel: Of -504
05B9-

Gemini Marketing Ltd, 18a Littfeham

Road, Exmcuth, Devon EX8 20G. Tel;
0395 265165/266832

Hestacrest Ltd, PO Box 13. Leiohton
Buzzard Bads LU7 0DG- T e l; 052-523
785.

Hilderbay Ltd, 8-10 Parkway, Regents
Park, London NW1 7AA. Tel: 01-495
1059,

Kemp Ltd, 43 Muswell Hill, London NIO
3PN. Tel: 01 444 5499.

MiCrol, Freepost, 38 Burleigh Street,
Cambridge CB1 IBB-
Myrmidon Software, PO Box 2. Tad-
worth. Surrey KT20 7LU.
Oxford Computer Publishing, PO Bnx 3B,
Oxford.

G A Rooker. 20 Vaughan Avenue, Lon-
don NW4

Sinclair Research Ltd, Stanhope Road,
Cambertey, Surrey GUI 5 3PS.

The Software Workshop, Yew Tree, Sel-
bourne, Hampshire GU34 3JP-

Tasman Software, 17 Hartley Crescent,
Leeds LS6 2LL

Transform Ltd. 41 Keats House, Por
Chester Mead, Beckenham, Kent. Tel:
01-SSB 63SO.

Work Force, 1 40 Wilsden Avenue, Lu-
ton, Beds.

SINCLAJR USER Annual 198-f

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Eric Deeson considers uses in the school

MANY YEARS AGO, in the
1970s, the use of computers
iti The home was an oddity.
Now something like five percent of
British families have computers among
their prize possessions. That is higher
than anywhere else in the world and
Sinclair Research must take a great deal
of the credit .

In the 1970s the use of computers in
school? was also an oddity. Now almost
every British school has one or more
among its resources for learning. That
is higher than anywhere else in the
world, too, and again Sinclair must take
a great deal of the credit.

In the former case, Sinclair credit is
due to the fact that the machines head
the list of sales to homes. That is not the
case in schools, where teachers' wishes
have so often differed from the ideas of
central Government and local advisers.
Credit, however, must still go to Sin-
clair, in that its activities increased com-
puter awareness in the country in
general and that increased awareness led
to the decisions to spend money widely
on educational computing.

It is difficult to employ statistics
alone. It is certainly clear that the num-
bers of schools offering computer activi-
ties, and the numbers of candidates in
associated public examinations, have ri-
sen at the same explosive rate as general
sales of micros for less than the £500
mark. Data from other countries is diffi-
cult to obtain and far less instructive.
Even in the U.S., Japan and Australia,
all reasonably well along our road,
home computing is still for the tiny
minority of middle-class folk and few
schools possess, let alone use, micros in
the classroom .

A primary school head I know, on a
recent visit to Japan, asked to see some-
thing of educational computing. His
request was received impassively but
several days later he was taken to a
central Tokyo school. It was a pleasant
place, with all the signs of great expen-
diture, and it had a "computer room".
That room contained 12 posh micros,
all new, and a pile of boxes hidden in a
comer. No children, no teacher in
charge. Was it a put-up job?

How do ZX micros compare to others
in educational contexts? First, I should
note what the others are. There are two
computers claimed by their manufactur-
er as the only machines designed
specifically for education. It is certainly
the case that very few, if any, homes
have them. The manufacturer is Re-
search Machines Ltd of Oxford and the
micros are the five-year-old 380-Z and
its one-year-old sibling, the 480-Z Link.
Both are massive and costly. They will
probably always suffer from inadequate
software support because the numbers
in use are so small compared to those of
micros which are also marketed to the
general public.

The 380-Z and 460-Z are certainly
pleasant machines but their size and

'Perhaps no local

authority knows the

facilities in its

schools*

cost and lack of support mean they will
never take computing to the masses of
pupils in a school. All the same, some
local education authorities continue to
restrict schools to RML machines for
various and, in my view, inadequate
reasons. I fear that in the areas of the
country concerned, pupils and teachers
will not progress happily towards com-
puter confidence.

The Acorn BBC micro is growing
rapidly in importance as a school ma-
chine, just as it is taking a good share of
the richer home market. Although there
are too many versions for comfort —
difTerent models, operating systems and
Basics — it has much more potential for
education than the RML competitors.
It is cheaper and much easier to move
around and there is an impressive vol-
ume of reasonably good educational
software available for it. Even so, I am
less than happy at the implications in
Acorn advertising that 70 percent of
micros in schools are BBCs.

There are other reasonably popular
educational machines — popular but in
an overall small minority. They include
the Apple — especially in Scotland —
the Tandy TRS-80 and its clones, and
the Pet. The Commodore 64 has made
surprisingly little impact on schools as
yet and the Vic-20 none, but it is likely
that the Electron will make inroads in
due course.

Having made a few vague statements
about the popularity of different micros
in the educational scene, I wish 1 could
be less vague. There was a flurry of
small and large surveys two years ago.
That was before the BBC had arrived
and before the ZX-81 had a chance to
make much impact, so the results are
almost meaningless. Since then little
hard information can be added to rein-
force impressions.

Data from two of my recent small
surveys of school machines perhaps can
add a little. The figures are 35 percent
ZX-81 /Spectrum, 29 percent 380-Z/
480-Z, 17 percent BBC, 19 percent
others — crude figures from crude sur-
veys but perhaps indicating at least
something about BBC advertising.

There are various reasons for the lack
of adequate data. The first is that per-
haps no local authority knows the corn-
puling facilities in its schools. That is
partly because computing advisers, if
they exist, have vast amounts of work to
do. Probably even most head teachers,
at least at secondary level, could not say
what equipment is available in their
schools. I have to think hard what we
have in my department. II" you want to
know, it is seven Ca I texts, two Cro-
memcos, two BBCs, two ZX-Hls, a 380-
Z and a terminal. No-one else knows
that, apart from the computing teach-
ers.

The second reason for the lack of data
is the multiplicity of sources. Many
schools receive at least their first ma-
chine through parent-teacher associ-
ations, as gifts from local benefactors, or
as prizes in competitions. Many others
have bought equipment from science,
mathematics or technology budgets. In
all those cases, I am sure, Sinclairs have
scored more heavily than other ma-
chines, being so inexpensive and so
well-known outside the staff room.

The likelihood of such unconvention-
al acquisitions of micros is particularly
high in areas where an authority has
told its schools to buy only RML equip-
ment. Teachers see a different need for
computers than many advisers and they
have often been determined to have a
ZX, whatever official policy may be.
The main reasons for that determina-

nt

StNCLAJR USER Annual IM4

tion are, of course, price and availability
of software and other back-up resources.
What then are the needs for comput-
ers in schools? I shall not say much
about that as the uses are fairly obvious
and well-documented in magazines and
books. There is my Spectrum in Educa-
tion, for instance. Broadly speaking,
computers are used in schools for these
main purposes:

To give pupils and staff experience in
using them, an aspect of computer
awareness or information technology
courses.

To extend the possible approaches to
teaching specific topics — computer-
assisted learning we call it in the trade.
To investigate control/data capture
applications.

To provide the means of practical
work in formal examination courses.
To assist with administrative tasks.
For the first three purposes the ZX
machines win hands down. They are
inexpensive. You can equip a room if
you wish with 12 Spectrums in a net-
work, plus MicrodriveSj two ZX print-
ers and a better-quality printer for less
than £5,000. That sum would buy you a
system based on only two 380-Zs or, if
using BBCs, five or six machines. Pass
over the permanent network idea and
the ZX way gives you sufficient power
for every teacher to have good access,
even in a large school-

Those teachers would welcome the
second huge Sinclair advantage, the
mass of cheap, fairly good learning soft-
ware available for home and schools
use. Not many of us have the time to
develop many good programs for the
purposes of our colleagues. There is
also in die Sinclair case a wealth of
magazine articles and books^ again sav-
ing the individual a vast amount of time
and frustration.

It is only when one reaches the last
two educational applications in my list
that the anti-Sinclair case becomes sig-
nificant. Yet, even there, we find ZXs
in positions of strength around the

country. Many schools base even ad-
vanced level programming courses on
ZX-8 Is and Spectrums and many teach-
ers have at least some administrative
packages up and running.

I am preaching to the converted^ of
course. If you are reading this publica-
tion you will already believe that Sin-
clair micros are the greatest. Be aware,
then, that not everyone agrees with you,
and in the corridors of political power
fierce batiks will still have to be fought
on behalf of Britain's youth,

What does Britain's youth need?
Why did I begin by saying a short
prayer of thanksgiving to Sir Give Sin-
clair? tn my opinion the pupils in our
schools need and want to be able to
acquire a high level of confidence and
familiarity with computers. Computers
will offer more and more threats to
society — to privacy, employment, free-
dom, peace — and it is essential that
every citizen knows that the machines
are no more than friendly slaves.

By the end of the decade it is likely
that powerful, fully-portable micros will
cost something like £10 and that the
present problems of inadequate support
will be on the way out. When that day
arrives I would hope that as many
members of the world community as
possible will be able to have such a
machine and be able to enjoy, welcome
and benefit from its use.

The only way we can approach even
feebly that state of readiness is to maxi-

The appearance of the BBC machine
is helping significantly but ZX-81s and
Spectrums remain the only sign of sal-
vation. One large authority in Britain is
going the other way. It is introducing an
unknown business machine costing
£2,000 as the standard. That machine
has no colour nor sound and only block
graphics, 1 understand it does not even
have a manual.

While that kind of approach con-
tinues, educational computing will be
for only a small minority. There is no
way that all pupils will treat micros as
friends — no way will many teachers
even find the machines of use in their
work. The computing teacher will reign
as a high priest over a mystical temple
and a small band of unintelligible wor-
shippers. That is an abhorrent picture.
Three-and-a-half years ago I founded
the Educational ZX Users* Group with-
in MUSE, the British educational com-
puting association. EZUG grew out of
all recognition, far beyond my ability to
cope. It showed me that thousands of
teachers and parents were convinced of
the value of the Sinclair approach to
computing in schools. Now EZUG is
re-absorbed within MUSE, its function
as a banner-waver fill filled.

All the same, though the banner-
waving is over, the battle for recogni-
tion won, the war is still a long way
from a conclusion. ! hope that the
conclusion will be computers accessible
and valuable to all in our schools but

'Educational computing remains fossilised in
the approach of the early 1970s. Too many
schools have massive unsupported machines
with which user-friendliness has no meaning'

mise the use of computers in schools,
colleges and homes. They must there-
fore be as cheap, portable and powerful
as possible. They must be supported by
plenty of software and print resources. I
believe that only the Sinclair range
meets that description.

Although many teachers feel that
way, educational computing remains
much too fossilised in the approach of
the early 1970s. Too many schools have
massive, costly, unsupported machines
with which the word user-friendliness
has no meaning. Few schools can offer
more than one micro per 100 pupils and
more than two teachers able to use the
equipment with ease.

there are many high priests in the corri-
dors of power who continue to fight for
computing for the few,

Alas, I fear that even if the war goes
our way, there still will be no time to
rest. There are few countries in the
world where the war has even been
declared, Sinclair is leading Britain to-
wards Computer-Assisted Freedom;
Britain will then have to do some lead-
ing, to give all human beings a brave
new world rather than a big brother
society.

Btic Dtaan, who teaches m Birmingham, organised
the world-wide Educational ZX Usen ' Group and k
honorary editor vf ihe MUSE magazine, Comput-
er* in Schools,

SINCLAIR USER Annual 1984

19

John Gilbert reviews more complex games

Arcades brought
into the home

A LMQST every major type of
l—\ arcade game has been simulated
A. JLon Sinclair computers. There
are also new games which have an
arcade format but have evolved on a
microcomputer. The Spectrum is an
ideal machine on which to play arcade
games. The quality of them has im-
proved substantially since the Launch of
the machine. Some oF the first arcade
games to be produced for the Spectrum
were versions of Space Invaders, the
game which started the arcade craze.

Spectral Invaders was the first to
be announced by Bug-Byte, which was
already renowned for its arcade and
adventure games on the ZX-81. So far it
is i he game which most closely resem-
bles the original arcade version. Al-
though it is slow il is difficult to score
points, as you can fire only one laser
blast at a time.

Another invaders game. Space In*
t ruder*, was launched at about the
same time as Spectral Invaders. The
game is much faster and is recommen-
ded for those who like to keep their
fingers on the fire button and amass a
big score. The only criticism is that the
aliens and rnothercraft are very small
and the mothership is blue on a black
background and so is very difficult to
hit. Apart from that Space Intruders
from Quicksilva is good value at £5.95.

Namtir Raiders, for the ZX-81, is a
space invaders game with a difference
from Artie Computing, The player shrill
has to face the hordes of aliens which
come down the screen but the laser base
can be moved up and down as well as
left and right.

The player has five laser bases during
the game and they can take only five
hits from alien bombs. There are three
levels of difficulty— easy to impossible.
The game, costing £3.95, is addictive
and the graphics are neither awkward in
design nor jerky in movement.

The game which is gaining popular-
ity with 48K Spectrum owners is Time
Gate, from Quicksilva, The authors
claim that it is the ultimate in 5D arcade
space action. The game is loaded in two
partSj the first being a lengthy instruc-
tion manual After the manual has fin-
ished you can load the game. The object

is to destroy a race of aliens called the
Squarm who are trying to colonise
Earth, The enemy fighters are also seen
in 3D and so are the planets on which
the player can land to refuel and repair
the ship. It is by far the best arcade
action game so far for the Spectrum and
costs only £6.95.

Asteroids is also becoming popular
on Sinclair machines. One of the first
companies to launch a version for the
ZX-81 was Quicksilva. It was a good
version on such a small machine and is
still proving popular,

Quicksilva has also introduced a
Spectrum version called Meteor

Storm. It has the added attraction of
speech before play. It is difficult to hear
the words but we are informed by the
aurhors that it says ''Meteor Alert . . .
Meteor Alert , , ,". Meteor Storm is a
novel version of Asteroids and costs
£5.95.

Sinclair Research has a good game of
asteroids, called Planetoids, in its new
Spectrum Software library. The aster-
oids are in 3D and much careful design
work on both the asteroids and the
player's ship seems to have gone into
the game. Planetoids costs £5.95.

Artie Computing seems to be the
only company to have produced a ver-
sion of Galaxians for the ZX-81, ZX-
Galaxians looks like Space Invaders
but the invaders are 'V 'shaped and are

supposed to be inter-galactic birds. The
birds swoop from formation and bomb
the player's laser base, ZX-Galaxian is
slow in action but can still be a very
addictive game. It costs £4.95.

Defender is still a much-sought-after
game in the arcades and Artie Comput-
ing took advantage of that early by
producing a version for the ZX-81. The
graphics are not particularly interesting
and the spaceship which the player flies
across the landscape is made up of a
series of blocks which look only slightly
like a ship.

Despite those criticisms, the original
idea behind the game is still there and
the Artie version can be exciting, as you
see the enemy ships rushing at you from
the other side of the screen.

With the arrival of the Spectrum,
many manufacturers found an interest
in the arcade game Scramble. The
best and fastest version so far is from
Mikro-Gen. In the game you have to go
through caves which become smaller
and smaller as it progresses,

The game becomes progressively
more difficult and can be run in slow,
normal and fast modes. It costs £3.95.

Silversoft has a Scrambk-type garne
calkd Ground Attack. It works on the
same principles as [he Mikro-Gen game
but is much slower. There is a good detl
of blank screen between game rounds
and the average waiting time between
rounds is 15 seconds. Ground Attack
costs £5.95.

The range of arcade-type games on
Sinclair machines is always increasing,
Manufacturers seem to feel safe in pro
ducing standard arcade games such as
Space Invaders and Scramble, Those
games, especially for the Spectrum, are
becoming more imaginative and the
graphics and sound more impressive.

Manufacturers have to be careful
about copying ideas from other games
but with the imagination of some of the
firms in the Sinclair market, children
and many adults will be kept happy
with arcadetype games on the ZX-81
and Spectrum for a long time.

Space Invaders games have now been
overtaken by Pacman in popularity.

Sug Byte. 98 100 Tlw Albany, Old Hall Street.
Liverpool L3 9EP

Quicksilva, 32 Norttianrt Road, Southampton SO?
0PB

Artie Compline, 39G James Reckift Avenue, Hull.
North Humberskie,

Sinclair R*S*»rch, Stanhope Road, CambHrley,
Surrey GUIS 3PS.

Mikro-Gsfl, 24 Agar Crescent, Bracknell, Barkshiru
RG12 2BK

Silversoft, 30 Orange StrBBl, London WC2H 7ED

20

5LNC1 :\Ik USES Axtmai 19S4

MIIMAL

T

W|**X

VAMPIRE VILLAGE

In a ruined castle near the village of Vladsdorf
%, lurks a vampire who roams by night.

As mayor you must organise volunteers to save

the villagers.
This is a REAL-TIME graphic

i adventure and every game is
different from the one before.

SPACE ISLAND

round a

-Jz : -

distant planet lead you into the st i ancient

civilisation that although lo;
dead, now threatens the pr€
This is a REAL-TIME graphic
adventure and every game i
different from the one before

BURS

w

f pad i. i

nd * <j< l t ant. " \

< ^m

n-ivi-nri'i-tM i»^rm.-wV

CITY

A unique REAL-TIME better-than-a-board game for 1-4
players that combines simplicity of use with complexity
pi form as the city you build takes on a life of its own,
i A functioning economic model for you to play while

'the Spectrum keeps track of the

Itime, the money, the properties
and the people.

rja Efra ibar ; Ifj 1 n gl

I 1 rm t-** 71 1 . . . J r D I

rri t i * ■ i ■ *-«

* >

1 ^SiUi

3 u

^

: - 3 -

i-^aE^pr:

ini=l3ii— »Q|.

ectrum *loK

All Super Value at Rec, Price £6.95

TERMINAL SOFTWARE

28 CHURCH LANE, PRE5TWICH. MANCHESTER M25 5AJ,

TEL; 061 IJ3 9313

Applications for
the Sinclair at
home and the office

Why not stop playing games and do some-
thing interesting with your computer? John
Gilbert assesses the software

BOTH SINCLAIR machines can
be used for storing data of any
kind, such as names and address-
es, telephone numbers and even an
ever-changing record of appointments.
The ZX-81 needs the I6R RAM pack
for any kind of data storage and both
information and program have to be
SAVEd together. That operation can
take up to six minutes and is not very-
reliable.

The Business and Household cas-
sette was one of the first packages avail-
able from Sinclair for the ZX-81. It
contains three programs. One will keep
a record of names and addresses, the
aax will keep a diary of events and the
final program will handle all your finan-
cial transactions.

The first two programs worked well
but the Bank Account program on
side two took six minutes to load and
SAVEing the program back on to tape
with the data proved very difficult.

The Business and Household cassette
may not be very reliable but it is good
value at £3,95.

One of the best data management
systems available for the ZX-81 is The
Fast One, from Campbell Systems, It
allows the user to set up files of infor-
mation in any way which suits him.
The program will sort and search for
specific bits of data and if numbers are
being used it is possible to total them.
The program is a step forward for the
ZX-81 and is very flexible. It will do
any kind of filing job, given the limita-
tions of the machine. The Fast One
costs £15 and has a comprehensive man-
ual.

Spreadsheet programs are an easy
way to store numerical data in a format
in which it can be used for calcula-
tions. The spreadsheet is a matrix, or
table, on the screen and any box, or cell,
in the table can be addressed by using
the letters and numbers which run hori-
zontally and vertically at the sides of the

sheet. This type of program can be used
to plan ihe family budget and calculate
automatically running totals of family
expenditure. That is only one of the
many applications for which it can be
used in the home,

MiCROt. produces a spreadsheet
program called Matrix Planner. It is
easy to use and has a spreadsheet of
eight rows by 31) columns. That con-
figuration can be changed by the user
through the program variables, Ap-
proximately 300 cells can be created in
the matrix before all the 16K of mem-
ory is used,

Sinclair Research markets two pro-
grams similar to the Matrix Planner
Vu-Calc is a program which uses the
spreadsheet. It has limitless possibilities
and can he used for financial modelling,
keeping track of bank accounts and even
setting-up scientific experiments which
rely on number-crunching for their out-
come.

The second is Vu-file. It is like Vu-
Calc but the user can only store infor-
mation and not perform calculations on

'There are programs

for data storage on

the Spectrum but

most of them can

be used only on the
48K version 5

data. Both programs are available for
the ZX-81 and Spectrum. ZX-81 ver-
sions cost £7,95 and Spectrum versions
£8,95.

The arrival of the Spectrum set soft-
ware houses the task of writing pro-
grams which can use data files separate
from the programs. It has opened the
way to storing large amounts of data on
cassette and, with the arrival of the

22

SINCLAIR USJ-R Annual fW4

Microdrive on floppy tape. There are
several good programs for data storage
on the Spectrum but most of them can
be used only on the 48 K version.

The Database from MiCROL. is
one such program. The files can be split
into documents. Those documents are
useful in splitting-up topics within the
machine. You can give each document a
heading, such as tax, income or budget,
and you can have several of them in
memory at one time

Documents are split further into re-
cords, with one record corresponding to
each datum. With that system it is
possible to do your tax and budgets at
the same time, without having to load
the computer twice with information.
The program can store up to 999 record
lines in memory. The Database costs
£9.95 and is complete with handbook.

The. Masterfile program from
Campbell Systems is the most compre-
hensive of the databases available. It is

'Most data

processing programs

can already deal with

more information

than the ordinary

user needs'

the successor to The Fast One for the
ZX-81 and provides fast access to large
amounts of information. The user can
also model the program to meet specific
requirements. Data can be sorted and
searched and reports can be compiled
using the system. Masterfile costs £15
for the 48K. version and £12 for I6K

The spreadsheets which proved so
popular with the ZX-81 are starting to
creep on to the Spectrum market. The
best, so far, are from MiCROL and Mi-
crosphere. Both are remarkably similar.
The MiCROL version costs £9.95 and
provides the basic calculating power of
most spreadsheet programs. It is easy to
use and can help the business or home
user with complicated calculations,

Omniealc is the spreadsheet from
Microsphere, It is ideal for someone
who has just found the spreadsheet
concept but it is also a very powerful
tool for anyone who has used one pre-
viously. The program seems to work
faster ihan the MiCROL spreadsheet
and information can be accessed almost
immediately.

The screen format is easily under-
standable and very clear for the first-

time user. The program contains a help
option which lists the commands avail-
able through the spreadsheet. Omniealc
costs £9,95. It is complete with a user
manual.

All-Sort is an interesting utility pro-
gram for the 48K Spectrum. It enables a
user to sor( data which has been set up
within a home-built program. The data
is stored initially in an array and All-
Sort can sort up to four of them at once.
It can be obtained from Alan Hirminger.
The program is useful and very fast but
at £18 exclusive of VAT it is expensive.
Listfile is a program which does
exactly what its name suggests. The
program allows a user to store lists of
data, such as names and addresses, and
to access that information very quickly.
Data is entered in blocks which can be
up to eight lines of 26 characters long.
An extra line, called the info line, can be
used to index information but that is
not printed-out when the printer is used
to list the information.

Listfile is available for the 16K and
48K Spectrum and can be obtained
from G and J Bobker. It costs £10 and
has full documentation.

Now that the Spectrum has arrived,
software manufacturers are beginning
to think about software uses other than
games on Sinclair machines. The data
processing programs could handle
many tasks which are centred on the
home. Databases, such as the one from
MiCROL, are useful for storing textual
information, such as a list of favourite
records or even knitting patterns.

The Microdrive can expand the data
processing capabilities of the Spectrum.
Information can be accessed more
quickly and as a result bigger programs
can be stored in memory and data can
be fed in bit by bit.

The capabilities of the Spectrum
can be extended in this way but soon
we will have to decide whether it is
necessary. Most data processing pro-
grams can already deal with more infor-
mation than the ordinary user needs, It
may be proved that that type of appli-
cation for the Microdrive is a waste of
time.

Sinclair Research, Camberfey, Surrey GU7&

3BR.

MiCROL. 31 Burleigh Street, Cambridge

CB1 1BR.

CampbeH System*. 15 Rous Road, Buck

hurst Hill, Esses IG9 6BL

Microsphere Computar Services Lid, 72

Rosebnory Road, London IM10 2LA.

Alan Fitminfler, 171 Heme Hill, London

SE24 9LH

G and J Bobker. 29 Chadderton Drive. Uns

worth. Bury, Lanes.

SINCLAIR USER Annua! i9S4

2i

New and varied life-forms now inhabit the
Pacman maze. John Gilbert investigates.

ng the Pac

PACMAN is part of what the
video historians like to call the
arcade maze craze. The game is
set in a raa?.e where a hungry Utile
round creature eats dots and power pills
scattered through the corridors. The
monsters are ghosts which hunt the
little man, and will eat him if he is not
agile enough to escape.

If, however, the Pacman eats a power
pill it can chase and eat the ghosts. The
original game was introduced to the
home computer market by Atari,
primarily on its VCS video system and
then on the 400 and 800 computers.

The first versions for other computers,
variously called Puckman, Gobbleman
and Scoffer, arrived shortly afterwards
and since then new versions have been
released almost every month.

Not surprisingly, the ZX-81 did not
escape the craze. The authors of
Zuckiiiiin, from DJL Software, claimed
that it as the first version of Pacman for
the ZX-81. The game runs in I6K and
is written in machine code, which gives
the scrolling routines and Pacman a
smooth movement. That is something
unusual on the ZX-81,, as most games
flicker slightly.

The game adheres as closely as possible
to the original and the limited graphics of
the ZX-8 1 do not matter much. One snag
with playing the game on the ZX-81 is
the membrane keyboard. Moving a
Pacman round the screen using it can be
difficult but not impossible.

Al the beginning or Zuckman the
ghosts speed on their victim and if you
panic trying to find the keys and do not
press them properly you are liable to lose
a Pacman or crash the machine. Once you
have a fair idea of the game, however, it is
surprising how quickly you can move the
Pacman around.

Zuckman is available for £5.95 on the
J6K ZX-81 and Spectrum. Super
Glooper is a version of Pacman, also for
the 16K ZX-81, which is retailed by
Sinclair Research. Glooper's task is
slightly different from normal. Instead of
gorging himself with power pills he has
to paint the maze. Obviously the ghosts
will not tolerate Glooper's antics —
perhaps they do not like the smell of

paint. The ghosts will try to kill Glooper
as usual but if he can get round the maze
and paint all the walls you have won.

The game is very amusing and is well
worth £4.95. The program will load in
less than two minutes, so you will not
have to wait six minutes to play the game.

The launch of the Spectrum provided
software houses with an excuse to try to
produce the perfect Pacman which
simulated the Atari version as closely as
possible but Atari guards its rights over
products jealously and investigated the
products of several firms in the ZX
industry.

The Abbex Spooky man game is the
most famous of the Spectrum versions. It
also looks most like the original. Most
games, until then, included anly dots
and power pills in the mazes. Abbex
included dots, power blobs, diamonds,
hearts, clubs, mean-looking ghosts and a
cute little Pacman which looks like a
diamond turned on its side.

The keyboard is divided into three
sections with left control on the left, right
on the right, and up and down in the
centre. The controls are very difficult to
master but, once you have done so,
usually with ihe aid of both hands, you
will be surprised at the agility you can
attain.

At times the game is almost impossibly
fast but Abbex estimates that the highest
score possible after every screen has been
cleared is 22,400. If you manage to reach
10,000 points you will receive a bonus
life. We managed to go i hat far only once.

Spookyman can be played by one or
two players, [f two play they take turns to
control the Pacman. Their individual
scores and the highest score are included
at the top of the screen.

There are two unusual features in
Spookyman. The first is that you can re-
Set the high score at any lime between
games; the second is that you can use a
joystick. The game is compatible with
theKempston joystick and once you have
seen it in action it is almost a necessity,
Spookyman is available from Abbex and
coats £4.95.

Gulp man is another variation on
the Pacman theme. The round
Pacman is replaced by a little man

24

SINCLAIR USER Annual 1984

running round the maze and the gliosis
become frowning faces which smile
only when ihcy have eaught Gulpman
The game is very complex and you
can switch to any of 15 mazes in which
to play. It is also possible to change the
tempo. At tempo one the speed is
bearable but at tempo 10 life is not
worth living.

The little man can fight back slightly
more easily than in other games as he
approaches with a fully-loaded laser
gun. If the ghosts gel too close you can
blast them away but only until your
energy runs out. It seems as if the space
age is overrunning everything.
Gulp man is available from Campbell
Systems and costs £5.95.

Hungry Horace, from Sinclair
Research, has developed a reputation as a
fun game; in fact Horace is almost a
legend. The game is a great improvement
on the original and remained at the top
of the software top ten for some time.

Horace is a large purple blob which
has sprouted arms and legs. He wanders
round the maze which looks like a park,
eating everything in his path and trying
to avoid the guards who act like ghosts
and try to capture him. He can scare away
the guards by using the alarm bell
situated somewhere in the maze.

If Horace reaches the exit of one of the
mazes he can enter the next maze and
continue to the next exit. The mazes
become more difficult as Horace
proceeds further in his adventure and we
managed to reach only the third maze.
With a large amount of skill, however, it
should be possible to go further.

Hungry Horace, for the 16K.
Spectrum, is available from Sinclair
Research and costs £5.95.

Although the arcade industry in the
States, and now in Britain, is declining it
is good to see that games concepts like
Pacman are being transferred to micros.
Some of the Sinclair versions of
Pacman seem as good as, if not better
than, the original Atari version. Games
such as Hungry Horace are setting-up an
interesting mutation in the Pacman
concept. They also seem more interest-
ing than the original version because they
have added to the idea of Pacman. So far
as the consumer is concerned it is to be
hoped that concepts such as Pacman will
not be destroyed within the industry.

DJL Software, 9 Tweed Close, Swiridori,

Wfes, SN2 3PU

Sinclair Research, Stsnhape Road,

Camhefley, Surrey. GU15 3PS-
Abbex Electronics Ltd. 20 Ashlev Court,
Grear North Way. London, NW5
Campbell System*. IDepl. SUI, 15 Rous
Road. Buckhurst Hill, Essex, IG9 6BL.

SiNU-AJR USER Annua! S984

Backgammon has long been a popular game which requires a mixture
of luck and skill. John Lambert reports on three versions

Ancient game has varied
success on the Spectrum

BACKGAMMON is an ancient
game involving much more skill
than draughts, yet dependent
more on luck than chess. It is as old, or
possibly older than any of them. The
ancient civilisations of China, India and
Greece all offer possible birthplaces.
There are three versions of the game tor
the Spectrum by Psion, l&K; Hewson
Consultants, IGK; and C P Software,
4SK; all priced at £5.95.

Each cassette has instructions for
those new to the game. Those written
for C P are good, clear and detailed.
Backgammon is a complex game and
the notes make play easy for a complete
beginner. The Psion instructions are
equally useful but those provided by
Hewson are not nearly as well put
together and might be confusing for the
novice.

When playing Backgammon, the vi-
sual impact of the board and layout of
the 'men* is vitally important — you
need to be able to assess your position
and your opponent's at a glance, so the
graphics are a prime consideration.

On loading, Hewson offers a choice
of single game, points series, gambling
series or a demonstration game. The
latter is very helpful for the newcomer
and compensates a little for the de-
ficiency in written instructions. There
is also a choice of static levels and you
can choose who starts the game, al-
though, strictly speaking, that is against
the rules.

The board is swiftly presented but
unfortunately it is not easy to see, either
in colour or black and white. The 'men 1
do not stand out from the board and the
computer moves are made much too
quickly for the experienced player to
follow, let alone the novice, A record of
the moves appears on screen below the
table. The Hewson graphics are simple
and not very effective compared to the
others.

Load the C F version and you are
presented with brief instructions for
play* which neither of the others pro-
vides on-screen, but there is no choice
of skill level. The graphics are much
better than those of Hewson, though

the board is drawn very slowly 3 that
part of the program being in Basic. The
definition is good, making the men
easily visible in colour, and only a little
less so in black and white, but since the
points are not coloured alternately as
they should be it is often difficult to
iLi leu late your moves. In [his program
the chosen pieces flash before a move is
made so that it is easy to follow and a
record is kept below of the moves, but it

points with more than five men, the
pieces appear to stand on their edges to
make space, whereas the other two
games resort to using numbers in that
situation. When blots are hit, they trav-
el grace fill ly to the bar, where a maxi-
mum or two men of any one player are
shown at a time.

In the middle of the bar is the dou-
bling cube, which moves from player to
player in use. Hewson is the only other

'The CP graphics are much better than those
of Hewson, though the board is drawn very
slowly, that part being in Basic. The defin-
ition is good, making the men easily visible'

is SLOW and your moves have to be
entered singly, which can be frustrating
when a double is thrown.

In its normal fashion, Psion presents
a screen display for you to look at while
the game is loadings even though the
screen takes almost as long as the game
to load. Incidentally that was a black
mark for Psion; whoever drew its screen
should have realised that opposite faces
on a dice add to seven rather than
adjacent ones. That criticism, however,
should not detract from the spectacular
nature of board display. You select from
four skill levels, with a demonstration
game available, and then are given the
opportunity to input your own dice
throws. It is the only one of the three
which allows this, a feature which other
games programmers would be wise to
copy since your faith in the randomness
of the RND generator will be shaken by
the dice thrown in all the programs.

The board is drawn quickly with the
points coloured alternately in black and
white and the pieces, large enough to
see easily, four character squares, in red
and cyan. The definition is not lost
when using a black and white television.
The dice 'roll 1 in 3D up the screen and
the pieces move across the board from
point to point, making it simple to
follow the course of the game. On the

game to offer doubles but only in it*
gambling series.

Moves can be changed after they
have been made by use of the DELETE
key, the men re-tracing their steps
across the screen, EDIT elicits suggested
moves to help the novice player
throughout the game. The graphic dis-
play is well-designed and effective.

All the games use the conventional
rules of play, as published by Hoyle,
but for scoring C P has no doubling
option, an integral part of the modern
game. Hewson uses its own method of
calculating points instead of the accept-
ed one. Only Psion scores correctly.

Hewson plays erratically, sometimes
being very conservative and at other
Limes raking wild risks. Moreover, by
moving about frequently within its own
inner table it is unable to take full
advantage of the dice. When playing a
back game it does not persevere long
enough and on one occasion when one
of its men was on the bar and most of its
opponent pieces had been borne off
leaving a blot on the three, Hewson
threw five/three and came in on the
five, thus losing a gammon. Apart from
that instance it usually 'hits' at almost
every opportunity and so it can be
trapped by a skilful opponent. On the
whole the level of play, even at its

26

SINCLAIR USER Annnat 1984

highest, is moderate and does not pro-
vide a stimulating challenge to an exper-
ienced player.

It is interesting to note that M Male,
the author, also wrote the excellent air
traffic control simulation, Heathrow,
for Hewson.

C P is another fanatical taker, but
rarely takes the conventional precaution
of building houses in its inner table. On
the rest of the board its moves are
generally conservative but its defeats of
Hewson, as indeed when Hewson beat
it, depended on some very lucky dice
throws towards the end of the game.
The two programs are well matched,
their skill levels being about the same
and their strategies very similar.

Psion plays a much more sensible
game and provides more of a challenge.
It makes better and more frequent use
of the standard openings and its strategy
throughout the game is more consistent.
It protects its inner table and leaves few
unnecessary blots but once again when
playing a back game it tends to lack
conviction and runs for home too soon.
To test the abilities of the games a
'tournament' was arranged* Each pro-
gram played five games against each of
the others. The results, shown in the
table, were surprisingly even.

It was expected, on the basis of play-
ing the game individually, that the re-

sult would be l J sion first, Hewson and
then C P, None of those programs,
however, can assess the play of its oppo-
nent, which is why they fail to take
advantage of each other's faults. Human
players would assess and eventually pre-
dict their opponent's moves, frustrating

'Results depended

often merely on the

luck of the dice'

a back game by refusing to hit blots, or
avoiding blots left as obvious traps.

Since the programs cannot do that,
the Psion game, for example, fails to
realise that its opponents play consis-
tently badly and cannot capitalise on
that as a human player does. For the

same reasons, Hewson and C P opposed
each other three times with identical
strategies and neither was able to realise
that and alter its play accordingly. The
results therefore depended often merely
on the luck of the dice.

The Psion game is programmed en-
tirely in machine code and so uses the
comparatively small space available on a
16K machine efficently, even using the
spare space in the printer buffer for the
table of the positions of the men on the
boards. Now the Microdrive is available
i[ may be a problem to fit it in. On the
other hand Hewson and C P are written
predominantly in Basic, Hewson about
70 percent and C P nearly 90 percent;
that makes them somewhat cumber-
some and would, particularly in the case
of C P, welcome the use of a good
compiler.

RESULTS

Psion v.

Hewson

Hewson v.
CP

1
G

2

3
B

4
W

Psion wins 5/3

W

W

CP wins 8/1

G

W

W

CP v.

G

G Draw

Psion

W

W

W = Win G ■ Gammon B = Backgammon

SINCLAIR USER Annual 19S4

27

u

f

Tower of Babel
hits Sinclair

As more users become accustomed to Sinclair Basic

and its limitations they have turned to other languages

to help solve particular problems. John Gilbert investigates

the growing demand for new ways of conversing with

your machine., such as Forth, Pascal, Logo and Lisp.

BASIC, as used on the ZX-81 and
Spectrum, is. a high-level lan-
guage. That means that it is easi-
ly understood by human operators but
that the computer has to translate any
entry made by a user into the code
which it understands.

Basic was designed to help people
become accustomed to a computer and
was not written to perform any particu-
lar task. That is the problem with it
when compared to other languages.
Languages such as Forth and Fortran,
were written to perform specific tasks.

Forth has already been implemented
on the ZX-81 and some versions are
available for the 48K Spectrum. The
language was designed originally for
engineers who needed to process formu-
lae. It runs ar many times the speed of
Basic and, with graphics added to the
list of commands available, you can play
a good game of space invaders by using
it.

The most interesting aspect of Forth
is that you can define your own com-
mands using words which already exist
as part of the standard system. A
dictionary of those words usually is
accessible on the system using a list
command. For instance, if you want to
find the square of a number you would
use the standard word DUF, If you
want to find the square of a number
squared again you could define your
own word, for instance DUPD, by de-
fining it as DUF*DUP. All that seems
very complicated if you are used to
Basic.

Some languages require even more
discipline on the part of the program-
mer.

Pascal, for instance, is a language
which requires the programmer to de-
fine all variables and functions used
throughout the program in the first

section of the code. A program written
in Pascal must then be structured as a
series of routines, each routine being
relatively independent of the others.

The language is slightly more diffi-
cult to use than Basic as it forces the

.,-, r .,.„v ,-.*.■ J^J

'•iimm . . . it's not so much BASIC m EARTHY. "

programmer to think about how the
code is to be put into the computer,
which operations are to be performed
first, and where routines are to be
placed in a program, instead of deciding
what code you need for a specific job.

Children and schoolteachers are be-
coming interested in a language called
Logo, which has been imported from
the U.S. Its inventor is Seymour Papcrt
and embodied in it are several contro-
versial concepts which many education-
alists are beginning to question.

The emphasis of the language lays

with teaching children about mathemat-
ics through graphics shapes on the
screen and through the use of a robot,
called a turtle, which can be controlled
from a computer. The robot can be used
to draw shapes on the floor and puts
into practice the concept of learning by
experience.

fducarionalists in Britain are scepti-
cal about using turtles in that way. The
reason is that learning in British schools
has been, and still is, by the repetitive
rote learning method.

Some schools are experimenting with
turtles but the lessons taught using
ihem have been structured so that chil-
dren are still learning by rote and not by
experiment or experience.

At present, Sinclair Research is de-
signing a version of Logo to work on the
Spectrum. Edinburgh University is also
working hard to produce a floor turtle
for the machine. The language will be
supplied free to schools which choose
the Spectrum under the Government
Microcomputers in Schools scheme,

The artificial intelligence language
Lisp has already been released for the
Spectrum by Serious Software. Lisp is
used for list processing and programs
can be written which will act like intelli-
gent databases.

Serious Software has provided a data-
base written using the Lisp package. It
includes the names or a family group
with relations which they form to each
other. Using the program you can dis-
cover which members of the family
have children, which have brothers, and
whether those brothers are married.
The database seems intelligent because
you can ask it questions which are
limited only by your imagination.

Normal databases would allow intbr-
mation to be accessed only using such
techniques as entering a keyword to

28

SINCLAIR USER Annual 1984

find data. You can also use Lisp to write
programs which will seem to give mean-
ingful answers to entries you type into
the computer. The computer will select
an answer depending on the data, which
is stored in its memory and how it has
answered questions similar to the cur-
rent one.

Programs which simulate this type of
intelligent computer response have
been written in Basic. One such pro-
gram, Eliza, acts like a human psy-
chiatrist and many of the replies it
generates seem almost too much like
human response.

The Eliza program in Basic is amus-
ing but with large amounts of data in
memory the program will respond very
slowly, someiimes taking two minutes
to analyse entries. Lisp was devised for
thai kind of work and so it has the
advantage of speed over Basic in this
area.

Most computer languages were de-
signed with a purpose. Unfortunately,
languages like Basic have been corrupt-
ed and are now used for different pur-
poses from those which their designers
had intended.

Basic was not intended as a commer-
cially-used programming language for
the design of space invader games. Un-
fortunately, programmers can use only
the langauge available to them and on
the Spectrum that is either Basic or
machine code.

Sinclair is now making it possible to
use other languages but Basic is still the
must popular, not because people like it
better than other languages but because
very few people have had the opportu-
nity to use any of the others.

Only one small microcomputer has
been produced which will run a lan-
guage other than Basic, (he Jupiter Ace.
Sinclair is definitely an innovator in the
market, so perhaps a micro with a new
dedicated business language may be the
next step.

FORTH

Artie Computing. 396 James fieckitt Ave-
nue,. Huli, North Humberside. [48K Spec-
irum/ZX-Sl}.

Abersoft. 7 Maes Afallen. Saw Street,
Dyfed SY24 5BA. (Spectrum 4&K).
PASCAL

Interlace, Dept SU, 44-46 Earls Court
Road, London W8 6EJ (Book with Basic
compiler L
LOGO

Sinclair Research, Freepost, Camberley,
Surrey GUIS 3BR. (Spectrum - to be re-
iMMffl.
LISP

Serious Software, 7 Woodside Road. Bick-
ley, Kent BR1 2ES- {Sped rum 48KL

SINCLAIR USER Annual 1984

29

Writing programs is time-consuming. John Gilbert examines a
collection of cassettes which help to make the job much simpler

from

machine

THE BEST WAY To learn about
machine code is to use an as-
sembler. Machine code consists
of numbers but with an assembler the
user can write code in assembler lan-
guage, which looks more like Basic and
U easier to understand. The program
will then convert the user's assembly
language instructions, called source-
code, into machine code.

Although the ZX-81 has been around
for several years there are only a few
machine code assemblers available on
the marker for it. The only big com-
panies to produce assemblers for the
machine are Artie Computing and Bug-

Byte. Both built their reputations with
these assemblers.

The Artie assembler is a two-pass
program. It will permit full use of
labels, will inspect and modify registers
and also allows output to a printer. The
code to be assembled is put into a REM
sratement at the beginning of the pro-
gram and all code can be written in
standard Z-80 mnemonics. The assem-
bler will also assemble messages which
are to be used in programs into hexade-
cimal code. It costs £9.95.

The other best-seller is the Bug-Byte
ZXAS. The program is similar to that
of Artie but was launched in a blaze of

publicity as being the first machine
code assembler for the ZX-81,

Bug- Byte also wanted to be the com-
pany which produced the first assem-
bler for the Specirum but it was to be
disappointed. Wrangling within the
company between its programmers put
the release date further and further back
until the package became available early
in 1983.

The program is for the 16K and 48K
Spectrum, It is very comprehensive in
its options and very easy to use. As well
as assembling user machine code, it has
a full editor facilitv with which the user

W

SINC1ATR USER Annua! 1984

an view assembly code s delete and
insert, search for specific strings of Text
within machine code, and list all the
labels which have been specified by a
user in a program within a cross- refer-
enced table.

The editor will also reverse 16-bh
values, such as memory addresses, if the
user specifies that option. That facility
is useful when dealing with a large
number of 1 6-bit addresses in a long
program. The use of 16-bit values can
be a problem for beginners, who often
do not know whether or not to reverse &
number.

The program also has a good cassette
interface. Both the source code — the
user's — and the object code — assem-
bled-code can be filed on to cassette.
That means that source code can be
saved and re-edited when the user needs
it. The saved source code could also be
useful if the programmer wanted to
upgrade a program.

Unfortunately the manual, or lack of
ft, provides points against Aspect.
Instructions are written on a piece of
paper. They are just about adequate and
contain no examples. Aspect costs £ Q
and is available from shops such as W H
Smith.

Picturesque slipped its Editor/As-
sembler on to the market very quietly.
The program is for the 16K and 48 K.

into operation. The usual ORG instruc-
tion is included as part of the instruc-
tion set to define the address at which
the assembled code should be put.

The program display is interesting,
as the screen has a 40-column width and
is split into several fields which corre-
spond to those used in assembly lan-
guage programming, together with a
line number field. The cursor recog-
nises the end of one field and jumps to
the next automatically. That makes the

'One of the most powerful assemblers which
we have reviewed is produced by a small, and

Largely unrecognised software house. Crystal

Computing'.

Spectrum and is very powerful. It is
complete with a comprehensive user
manual which a complete beginner can
understand.

The Editor is the part of the program
which enters the source code. It is
possible to enter code in the same type
of format as a Basic program, as each
tine is given a line number. Unlike the
Basic system on the Spectrum, line
numbers can be generated by the pro-
gram automatically with the use of the
AUTO command. The use of line num-
bers means that the source file can be
edited quickly and easily.

When the source code has been en-
tered correctly and there are no bugs in
the text, the assembler can be called

entered source code easy to understand.
The Editor/Assembler is ideal for the
beginner and could also be a powerful
tool in the hands of a professional pro-
grammer. It costs £8.50.

The program which caused a buzz of
excitement in the Sinclair User offices
is probably one of the most powerful
assemblers which we have reviewed. It
is all the more remarkable as it is
produced by a small and, until now,
largely unrecognised software house,
Crystal Computing.

The program j Zeus, is a two- pass
assembler which allows the use of the
full Z-SO mnemonic instruction set.
Source code can be line-numbered and
an AUTO line-number facility is also

available. The program is accompanied
by the best manual we have seen for an
assembler. It contains step-by-step
instructions for entering and editing
source code. An example is included
which will, if entered correctly, colour
the screen white, the current ink colour.

The use of an example in that way is
good, because if you make a mistake and
the program does not w r ork you will
have to re-learn the instructions. If the
example works, users will have a good
understanding of how Zeus operates.

Zeus also contains several subrou-
tines which can be used within source
code. They include an INKEY$-type
function and print a character routine.
Other functions in the assembler in-
clude automatic re-numbering of the
source file, outputting of code to a
printer, and the reclaiming of 'old'
source files for further work. Zeus has
been aptly-named by Crystal Comput-
ing. It costs £8.95.

There are very few good assemblers
on the market although the big software
houses all claim to have the best avail-
able. It is, therefore, surprising that a
small company like Crystal should pro-
duce such an excellent assembler as
Zeus. The reason may be that while
large companies spend their money on
colourful advertising, smaller compan-
ies need to rely on very good-quality
products.

Artie Computing, 396 James Reckitt Ave-
nue, Hull, North Number side HU9 OJA.
Picturesque. 6 Corkscrew Hill, West Wick
ham, Kent BR4 9BB

Crystal Computing. 2 Aston Way, East Her
rington, Sunderland SR3 3RX,

SINCLAIR USER Annual !9&4

II

After dealing with assemblers, John Gilbert turns his attention to their

counterparts, the disassemblers.

Making machine code
easier to understand

THE TERM disassembler has
been used in many ways by
professional producers of soft-
ware to describe their products and
some confusion has arisen as to what a
disassembler should or should not do.
The strict definition of a disassembler
calls for a program which will translate
the numeric values of machine code into
the mnemonics of assembly language.
There are other packages which do all
kinds of things with machine code but
do not fulfil that definition. The correct
term for those packages is toolkit.

The mnemonics of assembly lan-
guage look like shortened versions of
Basic keywords. They are used to repre-
sent the machine code numbers which
computers can understand but which
human programmers still find difficult
to cope with in great quantities. It is
much easier to understand a mnemonic
such as RET : which means Return to
Basic, than its machine code counter-
part, which in this case is 20 1 .

Most disassembler packages include a
monitor program which allows the user
to change machine code stored in RAM
which has been disassembled. The dis-
assembler makes the editing process
easier, as mistakes can be spotted quick-
ly if the programmer has a disassembly
and not just a list of numbers which
have to be sorted.

When computers had just been in-
vented there was little software and

assemblers made things easier. You
could enter code in mnemonic form
using the assembler and check the code
using the disassembler.

When microcomputers were invented
the disassemblers used on the large
mainframe computers had to be altered
to work on the smaller systems, as many
of the instructions which were used on
mainframes could not be used on mi
cros.

The first disassembler to appear com-
mercially for the ZX-Si was ZXDB,
from Bug-Byte. The company has built
its reputation with that package along
with its ZXAS assembler and the reason
was because it was cheap and ran on an
expensive computer.

The Bug-Byte disassembler was fair-
ly standard in its performance. It al-
lowed you to specify the address, or
position in memory, at which you want-
ed the disassembly to start. The pro-
gram would disassemble one line at a
time and you had to press NEWLINE
for the next instruction in memory to be
disassembled.

The ZXDB for the ZX-&1 used two
fields, or areas, on the screen in which
to display information. The first
showed the address at which an instruc-
tion was located and the second showed
the disassembly of the machine code
instruction.

Other disassemblers, such as the Cry-
stal Computing Monitor and Disas-

'The strict definition of a disassembler calls
for a program which will translate the
numeric values of machine code into the
mnemonics of assembly language.*

languages such as Basic and Pascal did
not exist. Programmers had to use pro-
grams which consisted of long lists of
numbers. You can imagine the trouble
if those programs did not work. Every
number in the program would have to
be checked to see if it was correct.
The invention of assemblers and dis-

sembler for the Spectrum, use three
fields. The extra area on the screen is
used to display the numeric machine
code on which the disassembler is work-
ing. It is a good idea as you can check
the mnemonics and machine code
against each other, to see if the disas-
sembler is working correctly.

If a company produces both a disas-
sembler and an assembler it usually
makes both programs compatible. That
means that both programs can be put
into the computer to work together and
dispenses with the need to load one
program to enter code and then load the
next to check that the code is correct.

Having both programs in RAM at
the same time will make programming
in machine code quicker and easier but
the amount of memory left for machine
code programs will be reduced drastical-
ly. The advantages outweigh the disad-
vantages, though, so it is a good idea to
buy a disassembler which can be used
together with an assembler.

Two problems occur when a disas-
sembler starts to produce question
marks because it has not been pro-
grammed to recognise a machine code
instruction. One disassembler which
does not follow the Z-80 instruction set
is ZXDB from Bug-Byte. The program
uses 8080 code instead of Z-80. Instruc-
tions which are common on the Z-80 are
named differently on BO80. For in-
stance, LD in Z-80 is called M in 8080
code. Those two names mean different
things. The LD instruction means load
a register with a value, whereas M
means move.

Trying to use a disassembler which
does not understand the full Z-80 in-
struction set is like trying to use BBC
Basic on a Spectrum or ZX-81. As BBC
Basic is not the same as Sinclair Basic,
the machine would not recognise the
extra commands of the other language.
As a result, when buying a disas-
sembler, make sure that the program
understands the complete Z-80 instruc-
tion set and not just a subset.

Disassemblers can serve two pur-
poses. They can be used to view code
which you have stored m RAM or they
could be used to look at the RDM of the
machine

With a good disassembler you could
obtain a listing of the complete Sinclair
ROM for either the ZX-81 or Spec-
trum. If you knew sufficient about ma-
chine code you might also be able to tell

32

SINCLAIR t:sKR Annual 1984

/ :■■■■■ ':'

;

nuai 1984

how the ROM works. To investigate
the ROM, or go bus hunting in «> Y ou
need the proper kind of disassembler.
Picturesque produces a monitor arid
disassembler package which suits the
purpose. The disassembler has to pro-
vide facilities for output to a printer,
3$ the Basic interpreter and operating
system within the ROM are very lengthy.
A true analysis would have you jump-
ing to different parts of the ROM when
JP, or JumP f instructions are indicated.
JumP is similar to the Basic GOTO
instruction but there are many options
available with that command and the
disassembler will help you to spot them.

Your disassembler should be capable
of handling the RST instruction as it is
used many times in the ROM It means
ReStarT and the instruction provides a
quick entry point into the ROM for
programmers using ROM routines in
Their machine code programs.

The RST 10 instruction, for in-
stance, would send the computer con-

trol to the part of the ROM which deals
with the printing process. The routine
sets up the machine to display one
character on the screen.

Most disassembler packages on the
market for both Sinclair machines are
being sold mainly as an afterthought to
assembler packages. The disassembler
has a very important role in computing

'Many programs on
the market could
be streamlined.'

and the second-class sticker with which
it has been labelled is unfair.

A disassembler should be a necessity
when you are writing machine code
programs.

If you are to buy one, take as much
lime about choosing it as you would
when buying an assembler. In many
cases it will be the disassembler which

will disappoint you with its perfor-
mance and not the assembler.

For instance, the Bug- Byte ZXDB
was a breakthrough when it was
launched but with hindsight it is some-
what mediocre. The standard of the
documentation with ZXDB was far
from satisfactory; as a result, the pro-
gram was difficult to use.

Disassemblers are becoming more
complex all the time and there is not
much which can be done to improve
them. Many of the programs on the
market, however, could be streamlined
to fit into less RAM than is now the
case.

dK'tronics. Unit 2, Shira Hill Industrial Es
tale, Saffron Walden, Essex, CQ1 1 3AQ,

Crystal Computing. 2 Ashtor* Way, East
Herrmgton, Sunderland. SR3 3RX,

Picturesque. 6 Corkscrew Hill, West Wick
ham, Kent, BR 4 9BB.

SINCLAIR USER Ammi ISM

n

;s

New ground broken by
powerful architects' aid

Sinclair machines are regarded still as little more than toys. David
Marsh disagrees in this review of a new cassette

APART FROM generalised spread-
sheet programs of the Vu-calc
L and Vu-file variety, there has
been little or no Spectrum software
written for serious commercial applica-
tions. Something of a new departure in
that direction is a specialised program,
Beam scan, which is used to calculate
the sizes of steel beams used in building
construction.

The program is used interactively,
with the screen prompting the user at
all stages and asking for details of the
loads, A diagram of the beam is dis-
played on-screen, which makes it clear
exactly what information is being re-
quested by the computer. The program
seems well error-trapped and user-
friendly. When all the data is in, there is
a wait of about one minute while the
numbers are crunched and then dia-
grams are displayed giving shear force
and bending moment along the beam.

From its library of standard steelwork
sizes, the program recommends a choice
of up to eight suitable sections with
stress and deflection for each. All the
regular rolled steel joists, universal
beams, universal columns and roiled
steel channels in grade 43 steel art-
featured and a moment of inertia can be
obtained for timber beams, from which
it is a simple matter to choose a suitable
section.

The beam must be simply-supported
and single span Cantilevers are not
within the scope. That is perhaps the
only limitation worth mentioning. Any
combination of point loads, distributed
loads and uniformly-tapered loads in
any number up to a total of 99 can be
specified.

What is more, the distributed loads
do not have to extend to the end of the
beam. Within the designated span of
0.3 to 20 metres, it is difficult to visua-
lise any beam which could not be ana-
lysed by the program,

Point loads frequently consist of the
end reactions of other beams, Both end
reactions are given, which covers that
point and also is a great help in finding
the stress in any supporting brickwork.

Also given are the maximum bending
moment and shear force, the deflection
co-efficient, the permitted deflection
and optimum moment of inertia.

That would mean that other types of
beams, for example round or rectangu-
lar hollow sections, could then be cho-
sen using the data given in BS4,

For each beam size chosen, the I,/ry
and n.'"E" ratios are jjuven, unjelher with

permissible and actual siresses, aetua
shear stress and deflection.

All that information can be put into
the form of a calculation sheet using the
ZX printer. That can then be submitted
to the client or to the local authority
responsible for checking the design. Al-
though full data is given on the results
and the presentation is clear and con-
cise, perhaps some local authorities may
consider it a little too concise, in that
virtually no details are given on how the
answers are obtained. It is therefore
difficult to check the accuracy.

It is clear, however, from the printout
whether or not the correct data has been
typed-in and, of course, that is half the
battle. The fact that a computer print-
out is being submitted rather than the
more usual written calculations should
lend a reassuring air of professionalism,

It is also probable ihat in the perhaps
not -too-distant future when most calcu-
lations are made in this fashion, various
programs will become widely-known
and generally accepted in the profession
as being accurate. Some kind of type-
approval system might even be possible
so that checking would be limited to the
data output.

That would be in line with the pro-
cedure followed in other areas, where
certain materials, Tor example building
blocks, are given a certificate to indicate
that they comply with building regula-
tions, If that make is used, then no
further proof is required that they meei
the requirements. Extending the con-
cept to software seems logical and
j [most inevitable.

Beamscan is supplied recorded on
hoih sides of the cassette and is suitable
tor a 48K Spectrum, being about 35K.
It is supplied with a well-written man*
u&l which guides l he user through a
worked example and describes the limi-
tations of the program as 999KN for
each load to a maximum total load of
|0,000,000KN from the 94 loads men-
timed. They scarcely seem like limita-
tions when there are other costlier beam
design programs for bigger computers
which cater for a maximum of eight
point loads while others cannot calcu-
late the shear force or bending moment.

At £25, it appears cosily compared to
the usual programs in Sinclair User but
it is a more specialised item with a lower
volume sale than games or spreadsheets
and is much less expensive than any-
thing comparable.

It should be ideal for small architec-
tural practices or the many one-man
firms involved in smaller-scale building
works. Neither is it necessary to pay a
four-figure sum for the computer. The
whole system — 48K Spectrum, ZX
printer, TV- tape recorder and software
— can be up and running for slightly
less than £300 and will soon pay for
itself in time saved.

Beam scan is available from Beams-
can, 20 Vaughan Avenue, London,
NW4 4HU. Tel: 01-202 8656.

34

SINCLAIR USER Annual 19S4

The technique of 3D has been growing in popularity. John Gilbert
finds it is not always used in the best ways

Extra dimension adds
excitement to games

THREE-DIMENSIONAL games
are increasing in popularity and
software houses are beginning
to see that 3D techniques have great
potential in a market where Space In-
vaders and Pac-man are rapidly becom-
ing outdated,

Programmers are starting to use
sophisticated techniques to achieve
three-dimensional effects on the com-
puter screen which seem more life-like
rhan the two-dimensional space-battle
games.

The effects are difficult to create, as
the programmer is working in three
planes, or directions, instead of the
usual two. Most shapes are produced on
the screen using X and V co-ordinates
which correspond to the flat horizontal
and vertical dimensions. Three-dimen-
sional shapes are constructed using an
extra axis which, in theory, moves away
from or towards the computer screen,

The new axis is called Z and it is the
inclusion of that dimension which gives
the three-dimensional figure its depth
When a 3D shape moves up, down and
sideways it uses the X and Y dimen-
sions. When it seems to move towards
you on the screen it is using the Z axis,
which exists only in theory, as the
computet screen is Hat and two-dimen-
sional in shape.

J K Greye was the first company to
produce games using three-dimensional
effects on the ZX-81. The game was
called 3D Monster Maze and the play-
er had to move around a three-dimen-
sional maze to find the exit and also to
evade the deadly jaws of the dinosaur
which prowled around the corridors.

Even those critics who dismissed the
ZX-81 as a child's toy had to admit that
the program was innovative and well-
presented, Monster Maze marked the
rise of the use of 3D techniques on
microcomputers as small as the ZX-81
and Spectrum.

After the release of 3D Monster
Maze, everyone could see the potential
of three-dimensional games and utility
packages on small machines. Using 3D
techniques programmers can portray
events which seem real to computer

users when they are playing a game.

Three-dimensional effects also hide
the inadequacies oT the computers on
which games are played. The dinosaur
which chased the player around a mase
in the New Generation game was cre-
ated using the standard ZX-81 character
set. That is not noticeable when the
game is being played and you could be
forgiven For thinking that it used high-
resolution graphics.

The use of 3D gives a game added
depth but at the same time it can also be
used to disguise a poor plot.

The game from New Generation
Software, 3D Knot, is an example of
that. While the game has a basic plot it
is not deep enough when you strip away
the 3D effects. That does not make it a
complete failure in this case but it
points to the fact that three-dimensional
graphics are a means and not an end.

There are two types of three-dimen-
sional effect. The first, and simplest to
produce, is shown in the Artie Comput-
ing game for the 48K Spectrum, Com-
bat Zone. The three-dimensional
shapes are shown as line drawings with
no shading. That means you can see all

the lines of the shapes, including those
which would normally be invisible if
colouring and shading had been added
to the figures*

Combat Zone, like so many other
pieces of software for the Spectrum, is
not new in concept. It is a version of the
arcade game of the same name. Al-
though the graphics are reasonable the
animation of the line-drawn shapes is
very jerky.

The plot involves the player as the
last of a race of tank commanders.
Enemy tanks and diamond-shaped
spaceships are dotted round the land-
scape and it is the commander's job to
destroy them.

The game involves plenty of action
and credit must go to the programmers
who have managed to produce images
which do not bend out of perspective as
they move. Artie seems to have taken
the easy way out, however, as the pro-
gram is so slow that it must use those
notorious Sinclair line-drawing routines
which are in the Spectrum ROM oper-
ating system.

The Sinclair graphics routines are
not known for their speed, so it would

SINCLAIR I SER Annua! 1994

35

have been better for Artie to write new
graphics routines into the main body of
the Combat Zone program.

The second type of three-dimensional
Image is produced reasonably well in
the Quicksilva 48K Spectrum game,
Time Gate. The graphics for that type
of image are more difficult to product; >
as the programmer has to shade and
colour the shapes to produce a picture
which looks three-dimensional.

If the shading or the shape of the
image is even slightly incorrect the pic-
ture will appear to be distorted and the
effect will ruin the payability of the
game.

The three-dimensional effects created
in Time Gate show a slight distortion of
image, which can be noted when an
enemy ship approaches closer to the
viewing screen of the player's ship. The
enemy seems to unfold its wings as it
gets closer and in some cases it appears
as iT the fixed wings materialise from
nowhere.

No doubt Quicksilva would explain
that as a feature of the game but all too
often features such as that are errors and
are explained away too easily.

The ending of Time Gate is disap-
pointing, as the three-dimensional tech-
nique seems to have been thrown om of

the window. When you have destroyed
the enemy you must approach its base
planet. The planet becomes larger as if
an approach is being made but the
technique being used is so obvious that
it is embarrassing to watch.

The program uses what again ap-
pears to be the Sinclair high-resolution
routines to draw circles which start
small and continue to grow bigger. As
they increase in me the drawing pro-
cess slows and the technique becomes
even more obvious.

It would have been better to do what
New Generation did with 3D Tunnel
on the Spectrum and create several
separate pictures in memory to switch
on to the screen one at a time in
sequence. That will produce an animat-
ed effect.

If Quicksilva used that technique the
plane L could have been produced in
high resolution at several stages of ap-
proach and would have looked like a
real planet and not a rope mat .

Time Gate has its technical faults
where graphics arc concerned but it is
playable. The 3D Tunnel from New
Generation, on the other hand, has
what can only be described as brilliant
and imaginative graphics but it is
almost impossible to play to the end.

The game lakes you and your laser

base through an underground tunnel
inhabited by rats, spiders, toads and a
very impressive tube train. Unfortu-
nately so much memory seems to have
been used to create the three-dimension-
al effects that the movement of the
player's laser base is awkward.

More attention could have been paid
to that area of the game, as movement of
the base is not smooth or quick enough.
That is understandable^ however, as a
great deal of memory has been used to
produce the displays. Apart from that
problem 3D Tunnel has the best graph-
ics for a Spectrum game.

There are still very few H3 games for
Sinclair machines, although those avail-
able give confidence that this sphen is
developing in the proper way.

In the next few months we could see
a move away from 3D arcade games and
into 3D adventure games. There arc
already a few graphics adventures on
the market but they do not use 3D.

As 3D techniques are developed,
computers will be better able to produce
simulations of the real world. Adven-
tures will become more exciting and
arcade games more dynamic. The 3D
field is, however, just starting to de-
velop but it has a long way to go before
perfect holographic images can be pro-
duced on a small computer.

EDUCATIONAL SOFTWARE

PRICES DOWN
PRICES DOWN

THE MICRO MASTER SERIES

FOR ANY SPECTRUM
(designed and tested by teachers)

The FOUR RULES OF NUMBER (for 7-13 years) ■ A cassette of 5 programmes designed to

increase calculation speeds to a very high standard. Computer adjusts to age and ability. Down

to £9.90 (previously £11 70).

LANGUAGE DEVELOPMENT SERIES (for 7-13 years) — 10 programmes per cassette

dealing with VOCABULARY, SPELLING, VERBAL REASONING and KNOWLEDGE OF

THE ENGLISH LANGUAGE. Designed for 11 + , Common Entrance etc., but also useful for

remediation. Down to £5,90 (previously £7.90). Please state AGE when ordering Language

cassettes.

One of each of the above — £12.70

PREVIOUS CUSTOMERS/ENQUIRERS - MUST quote registration number to deduct as

follows from the above prices. 0000-0999 deduct £2.50. 1000-1200 deduct £1,50. 1201-

1500 deduct £1.00.

Cheques /POs to
MICRO MASTER, c/o Dr Glasson,

94 Airedale Avenue, Chiswick, London W4 2NN.
VISA purchases or enquiries Tel: 01-747 1373

TRADE ENQUIRIES WELCOME (sale or return)

16

SJNG1 .A! R USK R ,4 nnuat 1984

Extend your 16k
Spectrum to 48k for
just*2300.

And get a Free
program worth£4*50

into the

bargain.

Js the manual past chapter 24 a mystery to yini? "Beyond Htmmm
ihows 48K Spectrum users huw xv PEEK and It )K1 systems
variables, how 1» manipulate the display file, Iwha.' 10 COMJol iht»
attributes, how in find out how much i spare memory i* left «*"d much,
much more. With the SP4£lh»S pnjgrani is href. t>n its im £4.50.

SP43. 32K Me mory Extension with Program - £23.00

Now, our SP4S offers even better value.

Because no*; we're not only offering you the facility to up-grade your
16K Spectrum to48K uye're also offering you the opportunity lo be able to utilise
this vastiy emended memory quickly and easily

For E23 aU you need lo do is plug the chip-set into the sextets provided
by Sinclair on your issue 2 (or £35 for issue 1 } and. you haw a standard 48K
Spectrum fully compatible with all Sinclair add ons arid very low in power
BorauncAon

There is no soldering req uired.

Rtting end removal are easy.

And the SP4S carries our full warranty arid Is upgradable,, on a part
exchange basis, to SP80.

Then all u hj need lo do IS LOAD our specially written 48K guide
program. 'Beyond Ho«2ans\ and youi48K computer will guide you through its

With no need to labour through manuals.

This will saw you rime., because we ail know how easy it hi to get lost Willi

tnerncwvmaps

SP80 teged 64K memory extension - £46

The fitting, power consumption and add-on compatibility are identical to

die SP4S (Issue 1 Version £501.

ll can be used as a standard 48K, but software instructions can switch to a

second page of 32K

But this is not recommended for the complete beginner. ^^

Yet it is of tremendous benefit to the serious user. And an SP»J K JK1 1 1

campileTtMll be available in late September.

For a fit and test service a! our premises £3, and by registered post L i .

MAXIMEM ZX81 . 32K - £39 (PUUS ONE U SED IK

The MAXIMEM 32 and £4K is a modified ZXH1 and nod just a RAM

pack It fits inside the ease.

We also give a ax- month guarantee on the computer, regardless ottne
age of wour trade in ZXK1

The extra memory uses only a quarter of the power consumption of a

lblKplug in meiiiyryai^dhDesrKrtinterferewithanyst^^
printers RS232 Of other interfaces

Z XSIowlo ad eT - £10

The ZX Skjwluader is a software masterpieoe that will help you to LOAi i
ZX81 programs onto a Spectrum, saving fiuurs ol typing "me

The Next Robotics Exclusive The Tri cks! it k

This new JoyaBck is a revolution in computer games control. With our

Trickstick from one to eight players will be able to play simultaneously
It will be on sale soon - see our next advertisement.

I Allc*oduct!it]nlhiurdwJbrmaieinaockalltMtimeo*gcanuiopff«4 Same day dispatch
for phnned Access and Visa oidm
To East London Rnbntics Ud: Mease send by return < tick items reqfuiredl

1 MAHMB43SK(e39')64K{£S9| * lkZXSl

□ SP48 I Issue i E3S) (Issue 2 L23> .

□ 5PaH!s*ie.JLW)(fcaue2£46l

□ SLDWLQADEKeiCi -

lJ W YOND HOKtf ONS" program E450 ,

1 I hwcaiaJoijuirlSAEoriM. ■

FbstayeO.ijap lanctowa 1 1 m i u* 1 * ■> fai -

,MyA : ">io is

I I I I M I 1 I I I I 1 I I 1

Name.
Addles

F-ast London Ffcjbotkx Ltd.. Gate 1 1 , Ruyal Afcert Dock Lxindon Elb
2A I lour Lnframaliun Service

m 01471 3308 EAST LONDON

Z4 Hour Access, and Visa f wdtnrnj
-Mul4»471S

Special Enquiries Tel. 01 474 44W
!i ex SSIU7I

KB

CA5I LWINUkJ'lN ,

KDEDTIBS'

SINCLAIR USER Annual 1984

M

i

DESKTOP CONSOLE FOR ZX SPECTRUM ZX-81,
SMALL BUSINESS SOFTWARE AND SPECIAL DEALS*

Luwwr
Prices

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Inr Lixxrlta Hifci most nf Ihr wn^ Delude can^irlE wrth Iwd buftl ri AxTKiilid pawn swilclies law In ZK

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Him CDMPUT^RHKK MJFTWME CWB Up 1? 20 PF (ml -ttlfH. m HHnr HjFtW** *i[*skA to U-r**n

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COMPIfTEMKK. 2 W>r«imY Devi. Hipvnb tfcglii. Wot Sujwj RHI6 IHJ Ttltphon: (04441 ibWSS

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SYSTEMS

Dept SUA (ZX81)

88 Harvest Road, Englefield Green,
Surrey TW20 OQR

compatible
printer

'A' Obeys standard
j^J^_ commands,

TT Printing spfled 120 lines per

minute maximum.
'JC Low cost paper supply.
^ Price includes power supply

and interfacing.

This thermal printer, now available in the U.K.,, is the
standard printer used with the American version of
the ZX81 . The printer plugs direct into the Spectrum
but has a through port allowing the use of additional

hardware through the same connector
--v^ The size of the printer is 7% x §36 x 3% ins.
'* ^b ***& ^^"v. attractively packaged in a moulded matt
v^> + £ f '■■., "^St black plastic case.

**&+£***£'' Pf. ^N. A separate power pack is supplied
^ °+ J^^^J^S. in a 2% x 3% x 2'A ins. case.

Credit cad facilities far

Two switches mounted on the printer allow for

on /off switching and also access to the test mode

and paper advance commands.

The printing speed in the sel f test mode is 120 1 ines

per minute.

The paper rolls are 41i ins. wide and 25 metres in

length.

Price include* - Printer, power
qp supply, full interfacing, one
"S> roll of paper, VAT

DEAN ELECTRONICS LIMITED

Glandtli Plrk Fvrnbank Road Aicot B»rk t hir* England

Tttf?hon> WinMieM How 10344 1 MMtl Talix 849242

DEALER ENQUIRIES INVITED.

£59

38

SINCLAIR USER Annua! 1984

Hardware World

J

The ingenuity of the peripherals
manufacturers has continued and Sinclair
Research finally launched the Microdrive.

Stephen Adams reviews another interesting
year for Sinclair users,

hmi tm

SINCLAIR USER Annual 1984

39

Stephen Adams summarises the add-ons

Ingenuity beats
Spectrum limits

THE BIGGEST blow to users of
non-Sinclair-produced equip-
ment was the announcement of
the Spectrum. It knocked most mem-
ory-mapped add-ons on the head, as no
provision for those devices had been
made. That was. because, unlike the ZX-
81, there was no way o f turn ing-off the
internal RAM from the expansion port.
The only thing left was for producers to
put things in the inputfoutput map or to
supply RAM packs or RAM upgrade
kits.

The I/O map was already full of
Sinclair devices, allowing the use of
only eight separate devices, if they
wanted them to be compatible with the
Microdrive- Nevertheless, ingenuity
brought forward a large number of new
devices after the initial shock had worn
off.

RAM kits for upgrading the 16K
Spectrum to 32K are now readily avail-
able for about £21. Fox Electronics, for
example, supplies a kit for £20.99 and it
has instructions on how to improve
your TV display. They are easy to fit
and now have simple instructions on
what to do, if you can overcome the fear
of opening the case. The kits are usually
identical to the proposed Sinclair up-

Microdrivr

grade but will fit only on model 2-type
Spectrums. East London Robotics can
also supply an extra 64K kit which is
paged.

For those with a model 1 Spectrum,
identified easily by the grey keys, there
is the choice of an add-on board made
by Downsway Electronics or the Spec-
trum 32 K RAM pack by Cheetah Mar-
keting, The Spectrum RAM pack will
also Fit on to any other Spectrum, as it
plugs into the expansion port.

Another memory-mapped device
available this year was in a surprising

'Printers and other

hardware devices

make the software

come alive'

place, inside the Spectrum 16K ROM
space. It was the Orme Electronics
ROM containing RENUMBER, block
delete of Basic lines and many other
useful routines in a 2K ROM. That can
be very useful, as it is immediately
available on power-up.

Sinclair
has also
provided two
new devices for
use in the ROM
space, which should
please hardware and
software users. One is the
Microdrive Interface One
which not only contains the con-
trolling ULA .md hardware to run
the RS232/network/highspeed cassette
Microdrive but an extra ROM which
can be used to write your own Basic
commands. The other is the ROM car-
tridge system available with Interface
Two,

The RS232 can handle a printer easi-
ly with its limited handshaking ability
but still is limited for input from an
RS232 device, as all that is under soft-
ware control and not a hardware chip.
The network is a very simple arrange-
ment which allows you to talk between
64 Spectrums but I have no doubt that
someone will write similar software to
use it with the ZX-81 through the
cassette sockets. Two books which
should help in this respect are those by-
Andrew Fennel and Dr Ian Logan.

The Fennel one also contains an ON
ERROR GOTO machine code routine
which should trap 90 percent of Basic
errors and send them to a program line
to deal with them,

Sinclair has also launched the
Interface Two, containing two joystick
sockets which will operate the first or
last set of five number keys. Thai will
mean that software will have to be
rewritten to use Sinclair joysticks, as
the accepted standard at the moment is
the one set earlier in the year by
the Kempston joystick interface which
operates as an I/O device, depending for
its decoding on A 6 only being low.

40

SINCl MK I SI-K Inmtal tm

Much
software ha*
already been con-
verted to use it and [
cannot see software
writers wanting to do it all
again. Programmable joy-sticks
are just starting to reach the market,
which will eliminate the need to re-
write the software.

For the Spectrum and soon the ZX-
81, the Stonechip one seems to he best.
For ZX-81 and Spectrum users, a
cheaper hardware-based version, the
Pickard controller, can be used as it fits
both computers by plugging into the
keyboard sockets. The AGF version
uses crocodile clips to set up the five
keys to be used; it is a little unstable hut
it plugs into the edge connector and
does not require entering the machine.
The Interface Two also has a single
ROM socket which allows you to use
Sinclair-designed cartridges. It is not
known whether software suppliers will
want to ity to fit normal ROMs to a
port like this. That, and the fact that
recording Microdrive cartridges is a
slow process, will limit the amount of
software available from software manu-
facturers an Sinclair devices. EPROM
software for ZX-81s is available from
Hprom Services and Audio Computers,
Both, however, concentrate on the
machine code user and not the games
player. The fall in price of the ZX-S1
and the amount of hardware available
for it has started to attract the business
user as a control processor for a robot or
controlling some industrial process.
That is because it contains all the re-
quirements of the development system
on one board — 2-80- A, one of the most
popular processors, working at

3.25MHz,

TV interface,

cassette interface

for program storage,

alphanumeric keyboard,

Basic as well as machine code

monitor for designing programs,

and an expandable memory map and

VQ map.

There is also a wide range of machine
code assemblers, dissasemblers,
EPROM cards and blowers, RAM, bat-
tery-backed memory already available,
costing just a few pounds. That to the
industrial process manufacturer is pea-
nuts, as a development kit from a chip
manufacturer would cost more than
£200 with far fewer facilities. The ZX-
81 costs only £45 with a massive I6K
memory included.

Plain-paper printer interfaces for the
Spectrum abound and Tasword, the
word processing program, can work
with most of them. Hilderbay and
Kempston provide software-driven
Centronics versions, while More* pro-
vides both RS232 and Centronics out-
puts. Deans also introduced its version
of the Times printer, which uses a
much better paper than the Sinclair,

Microdrive with, tnccrface 1

gives a clearer print in both black and
blue ink, and will use Sinclair com-
mands to control it, so there is no need
for extra software.

Printers and other hardware devices
make the software "come alive" and
that combination makes the Spectrum a
very powerful business computer.

That is the most important event of
the year, as the more software which is
written to use the large amount of
hardware, the more that hardware will
be used. Voice output units, modems —
to talk to other users or databases over
the telephone — RS232 interfaces and
light pens all rely on good software to
make use of them.

The Cheetah Marketing Sweet Talk-
er, for instance, works better because it
is accompanied by an instruction tape
which not only demonstrates how to use
the unit but also shows the user how to
structure programs to make it easier to
use in their programs.

Modems from Ma pi in, Ambit and
Micronet — for Prestel — will allow
users or the Spectrum and, in the first
two cases, the ZX-81, to talk to many
other computers. Some of them will be
other types of computers, like the BBC
and the Commodore o4. The others will
be maintained by public and private
companies which maintain large
amounts of information and programs
on their computers.

Micronet 800 is a database main-
tained on Prestel computers as a 24-
hour-a-day, seven-day-a-week computer
club. It has hints and tips on Spectrums
— ZX-81 s at the moment cannot use the
system — as well as news, free programs

SINCLAIR USER Anmuil 19B4

41

&;:

AGF programmable joystick

and a mail box facility- Keyboards and
consoles also have been making their
presence felt as ZX-81 and Spectrum
users want to upgrade their machines.
Plastic cases from W H Smith are about
the cheapest containers at £3.99 and
will take a ZX-81 or Spectrum, as well
as a few r add-ons. The d'Ktronics key-
board and case or that from Fullers
appear to be the most popular but
neither will allow the use of the Micro-
drive interface without taking it out of
its case.

The Filesixty button set is a cheap
alternative for ZX-81 users which gives
the advantage of spring-loaded key-
board the same size as that of Sinclair,
but without costing more than £10.

Golour for the ZX-81 is now available
in a simple form for all PAL television
users — that is., most of Europe, The
black box requires only two wire? to
insert between the modulator and the
breaking of tracks and can be re-con-
nected if required. The rest of the box
plugs into the back of the ZX-81 10 give
black characters on a choice of 16 col-
oured backgrounds or coloured charac-
ters on a black background from DDC.
It is also more stable than the Spectrum
and requires no extra memory to use it.
It will work even on a IK machine.

One device which requires extra
memory is the excellent High-res screen
— 192 by 256 pixels — and user-defin-
able graphics package made by Notting-
dale Technology Centre. It uses the
ZX-81 internal IK. RAM for its system
variables and 6K or memory for the
storage of the screen in the program. No
internal wiring is required, as the unit
plugs directly on to the back of the ZX-
81.

For the Spectrum, a unit has
appeared which will be of great delight

to children and disabled users. It is the
Currah microS pcech unit which plugs
in to the back of the Spectrum and, on
command, will speak the key pressed,
Thai happens during program input as
well as INPUT and INKEYS.

It requires no programming of the

Orrrte Electronics EPROM read card

speech by the user. Speech output can
also be programmed by using S$ to
contain the alphones — sounds which

ChMfah Sweet Talker

make up words — which are then spok-
en immediately. Thus input and output
can be spoken rather than read.

Tapes have been causing problems
ever since the ZX computers tame into
existence; the Spectrum is better than
the ZX-S1 but still can be improved
with some extra hardware.

Tape filters and switch-controlled
SAVE and LOAD devices are available
from several firms, like Abacus and
Elinca, There have now been three
Spectrums produced by Sinclair. The
model Is, which can be identified by the
grey keys or by looking through the
expansion interface and seeing an IC
socket on the left-hand side; the model
2s have the large, black, ROM chip
there. Those Spectrums need their extra
32K of RAM mounted on a printed
circuit board before they can he put into
the computer. There are no Sindail
RAM boards available for the machine.
The model 2s were re-designed com-
pletely by a computer and the ULA was
changed to get rid of an extra IC which
had to be inserted in the model Is, due
to a design error. The extra 32K of
RAM which can be added to 16K ma-
chine now requires only chips to be
plugged into sockets on the board.
Model 1 s and model 2s have had to have
an extra transistor fitted to prevent a
clash between the keyboard and the
UFA TV interface.

The latest model 3s have also had
their internal circuitry re-arranged and
the ULA updated to give a wider tuning
range on TV sets. It has also caused
some software problems, as the key-
board inputs are no longer held to
binary I — +5 volts — when not in use.
That was done to reduce the power
requirements of the I I A

42

SIM I AIR I M H Inttual \

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An entertaining, but thorough reference source

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4 programs for the young
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telling the time, shopping
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easy introduction to
computer aided learning.

G.C.E. "0" LEVEL

FRENCH VOCABULARY

REVISION

Six programs on one
cassette. The first 3
programs test vocabulary
under various headings:
eg "on holiday". Three
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homework tester,
common words and
phrases, and irregular
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GEOMETRY

6 programs of multiple
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covering properties of
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various polygons and
circles. All questions use
generated numbers. An
explanation of the correct
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We have a large range of
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I enclose crie.que/ p tot

44

St

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SINCLAIR

Programming

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During the year we published a series to

help you learn how to program and

occasional articles on how to add gloss to

your listings. We now collect them to make

a complete programming course.

SINCLAIR USER Annual !984

45

Follow route to
better programs

Basic Sinclair coding with John Gilbert

MANY PROGRAMS written
by beginners to computing
. show a lack of what profes-
sionals call structure. The structure of a
program is the way in which it is put
together and the order in which the
code— the language in which it is writ

be an aid in finding redundant code or
code which inhibits the flow of a pro-
gram.

The program flow is the way in
which the program will be executed. It
is important to have that correct or
errors will continue to occur in the

ten— is put down in the finished prod- program and the speed of the program

ucl will be slower.

The basic flowcharting symbols are
the Input/Output box, operation rectan-
gle and decision diamond and an
example of each is shown in figure one.
The I/O box is used to mark places
where an entry is made by the computer
operator, or when the computer dis-
plays data on a screen or printer. The
box can be used for all forms of input,
including keyboard, joystick, or even
punched cards on a large mainframe
computer,

When debugging a program, checks
for errors should first be made at those
junctions in the flowchart, as [he boxes
mark places where a user can crash a
program by entering the incorrect infor-
mation.

The decision diamond is the most

To help the beginner with how to
structure programs so that they wilt
work faster and occupy less memory, a
database is constructed which can be
used to store lists of information, such
as names and addresses or telephone
numbers. The information stored in the
database can be called back by typing-in
a keyword which corresponds to the
information sought by the user.

Before we start to do any coding it is
important to know about flowcharting.
A flowchart, such as the one in figure
one, is constructed before coding to act
as a guide to what the finished program
will look like. If it is written after
coding has been completed and before
The programmer starts to search for
errors— to debug the program— it will

Figures 1 and 2

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complex operation box in a computer
flowchart— and the most necessary. A
computer is distinguished from other
machines through its ability to make
decisions based on information. Usually
the processing oT that information will
provide a simple yes or no answer. The
inflow to the diamond descends verti-
cally and splits in two to provide the
yes/no options.

The option which contradicts the
program flow goes out to the side of the
box and can be directed up, to form a
loop until the action has been per-
formed correctly, or down iT alternative
action is required to that of the normal
flow. Finally, the operation rectangle is
used to show that the computer has to
perform some kind of calculation. That
may be adding numbers, assigning
numbers to variables, or scanning a
string of characters. The use of that and
the other boxes is illustrated in figure
one.

Flowcharts usually are constructed
before writing a program but it is a good
idea to draw up one from the finished
program to see if the program flows as it
was originally intended.

When drawing a chart the boxes
should be balanced as much as possible
to the left and right of the main stem of
the flow. The whole point of flowchart-
ing is to create an easily-understood
diagram. The labels inside the symbols
should be written in English and not in
Basic.

The diagram in figure one uses sever-
al decision diamonds and they branch to
both left and right. A flow on just one

46

SINCLAIR USER Anntut m

side of the diagram looks sloppy if there
are more than two decisions to be made.
The way not to structure a flowchart
is shown in figure two. The flow lines at
the side have been run together, making
it almost impossible to decide what
happens next. That is remedied easily
by making the chart longer and re-
structuring the lines into separate boxes
as shown in figure three .

When writmg a program it is a good
idea to draw several flow diagrams. The
firsr would be an overall plan showing
the sections of program to be written
and subsequent diagrams would expand
each box to show the How of the various
routines,

A program is structured in a similar
way to a flowchart- Most programs are
constructed in the way figure one
shows. The technique is called modular
programming because the structure is
broken into subroutines; of sections,
called modules.

The reason is to eliminate as many
GOTO statements as possible, or 10
make a GOTO statement jump only to a
part of the routine in which it is situ-
ated, i.e., to make what is termed a local
jump, or the control routine at the top
of the program.

The control routine consists of a
series of GQSUBs, It is the part of the
program which is used most, so it is the
first thing the computer encounters
when scanning the program. In that
way the program is faster in execution,
so it becomes more efficient.

A control routine can have two dis-
tinct structures. The first is used in a

game- type program. That type of pro-
gram will execute routines by going
down through each or the GQSUBs in
turn and then returning to the begin-
ning.

The other type of structure is that
which we shall use for the database.
The program will first jump to the
menu routine where the user will select
an option. Control is then sent back to
ihe control routine and, using a series of
IF , . . THEN statements; the program
will go to the subroutine selected by the
player. The control program will not go
down through all the GOSl'Bs but will
jump only to those specified by the user
through the menu.

Ihe database will function using a
keyboard recognition function. The
user enters a few words which act as a
key phrase. The program will then look
through the list, or file, of information
in the program and, if a match is made
between the key phrase and part of a
piece of information, that piece of infor-
mation will be output- The computer
will output all information which is
associated with the key phrase.

The program will also have to sup-
port separate data files and be user-
friendly so that anyone can use it. The
program menu will have search files,
display entries, load or save files, and
will create new files. The program
siructure will look like this from top to
bottom, with the control routine at the

top.

The complete flowchart of the data-
base is shown in figure one. Using that
chart it will be easy to translate each

operation into program code.

With programs such as the database,
which is being constructed, the screen
display is very important. The com-
puter uses the screen to display infor-
mation to a user.

Many people who use programs such
as databases or word processors will
know nothing about how a computer
works or what it expects as input. The
more information given to the user by a
program the better. That does not mean
clogging the screen with vast quantities
of text. Instructions on the screen
should be easy to read and well-spaced.
The clear screen command should be
used as often as possible to break-down
information into easily-read pieces but
at the same time the jump between one
screen of instructions and another
should be almost transparent to the
user.

The text must flow naturally and
there should be no illogical jumps in the
instructions. That is a matter of experi-
ence but the database has been designed
with clarity of insi ructions and prompts
for inputs in mind.

The most important instructions
should stand out from the rest. That can
be done by liberal use of the commands
BRIGHT, INVERSE and FLASH on
the Spectrum and the GRAPHICS
mode on the ZX-81.

Listing one is the menu subroutine
for the database. It is written for the
Spectrum but is easy to re-write for the
ZX-81. To do that take out the IN*

Figure 3

(7^*?J)

47

SINCLAIR USER Annua! 1984

VERSE in 1020 and 102 1, HRIGHT in
1021 and FLASH in IQ40. INVERSE
can be substituted with the GRAPH-
ICS inverse lettering of the ZX-81 and
the title MENU should have spaces
between each letter to make it more
prominent.

The menu should not be surrounded
by a border of a different colour, as that
can confuse a user and make the screen
look crowded- It is also important not to
use excess graphics commands, A dis-
play with FLASH or INVERSE all over
the screen is just as confusing as if they
were not there.

One other thing which people tend to
forget is that they have the use of all the
screen. Do not cram things into the
corners or sides of a screen. Titles
should be central and if there is only an
input prompt on the screen, a good
place to put it is the top left-hand
corner.

Listing one is the first module of the
program. If there is a menu in a pro-
gram it should be situated at the top of
the code after any single or array vari-
ables have been declared, as in line 100
of listing one.

The menu module will display the
options available from the program. Ask
which you require, put the number of
the option selected in a string variable
AS, and transfer to the control program,
also in listing one, at the top of the code.
The control program, consisting of a
series of IF . . . THEN instructions,
will then transfer to the subroutine
selected from the menu.

The two other modules which are
listed are for LOADing data files-
listing two— and SAVEing files— listing
three. They are for the Spectrum but
ZX-81 users can add toolkit routines
available from such companies as JRS
Software- They will handle data files for
the ZX-81. If you do not want to go to
that expense you will have to SAVE the
program and variables together.

ZX-81 owners will have to break out
of the program by erasing the left-hand
quote mark of an input and typing
STOP, Then type SAVE t( program
name". When LOADing it back in, do
the usual load but do not press RUN.
Instead use GOTO 200.

The SAVEd program can be verified
on the ZX-81 by re-winding the tape,
typing LOAD " ", and re-entering the
program you have just SAVEd. ir the
program has SAVEd correctly an 0/0
error code will appear; if not you will
get another number error code. If that
happens you will have to re-SAVE,

In the SAVE and LOAD routines a
file name is asked for in lines 4010 and

5010. On the Spectrum a tile or pro-
gram name can be only 1 1 characters
long. To prevent the program crashing
if the name typed- in by the user is too
long, lines 4020 and SO 20 will take only
the first six characters of a file name.
The other letters are cut olT or trunc-
ated. Truncation is also used to cut the
YES/NO inputs to Y or N.

The displays in both the SAVE and
LOAD routines are important. Error
messages should be displayed in the
same position on the screen every time
they appear. Every program should
have a standard error message area to
which the user will become accustomed.
In the case of the database, that is in the
middle of the screen, Also the error
message in line 800 is BORDERed in
red to warn the user that a specific input
is required.

Be careful about using the word "in-
put" in a prompt, as it is computer
jargon, The word "enter" is preferred
as is shown in line 1040 of the database.
The prompts and information in the
SAVE and LOAD routines may seem
simple and not worthwhile but the
writer knows about the internal work-
ings of the program and what to enter,
A newcomer to a program, on the other
hand, needs to be taken through it step

by step.

When a module of a program has
been written it is a good idea to test it on
a friend or relative who knows nothing
about computers. If they can follow the
prompts, leave the display as it is; if
they are confused, you know you have
more writing to do.

Data structuring comprises a series of

topics which most beginners like to

leave alone, unless they are doing O or

Listing 1

A level courses in computer science.
There is only one data structure in the
Basic language and that is the array. An
array is a series or table of data items
which are grouped under one name.
They are indexed using a number. Most
professional data processing programs
are not written in Bask but in machine
code, because of speed restrictions.
Also, using data compression tech-
niques in machine code you can enier
much more data into the machine than
would normally be possible

Databases written in Basic do not
often use arrays as it is better to use long
strings of characters into which the data
is put, or concatenated, as il is entered.
In that way a user does not have to
specify the length of a file or how many
data items can be entered as a m;ixi-
mum,

Arrays occupy more memory space
and their length has to be fixed before
data entry but sorting and searching is
easier to understand by using one- or
two-dimensional arrays, as we can deal
with data one dement at a time.

The file creation and data entry
routines of the database being con-
structed are shown in figure four.

The listings shown are lor the Spec-
trum but can be used for the ZX-81
with the changes mentioned earlier-
Line 100 oflisting one has been altered
slightly to contain another array, cS,
That array will hold the number of the
hl\i available space in a file, the maxi-
mum number of data items it is possible
to store, and the maximum length, in
characters, of a data item.

In the file creation routine the user
can define the file length and word
length but if they are over the maxi-

I

10©

4-00

500
&&0

70S
800

DIM b* (100,201

— O SUE* 1000
IF a*=i" THEN
IF a$="2" THEN
IF <>* *"3" THEN
XP 3*e"A" TMEN
IF a*e"S- THEN
INK S: CL5 :

T FLRSH liftT 10,8;

R IS": PAUSE 200
900 GO TQ 200

1000 PAPER 0: BORDER

LS

1010

L5

1020

1021

GO
GO
GO

GO
BORDER
"ENTER

sue
sue

&UO

2
R

i£0OO
3000

5000
&000

PRIN

NUrfBE

INK 4-

PfiPER 0: BORDER 0: INK 4*

INVERSE 1

PRINT INVERSE 0; BRIGHT l;
INK e;TflB 1*; "MENU"
1030 PRINT HT 5,7; "1 SEARCH flL

E ";RT 7,7, '2 DISPLttV PILE

,ftT 9^7j "3 LORD PILE
1,7; "4 SRVE PILE

'S CREATE FILE
104-0 INPUT • * * * INK &,
^NTER OPTION (1-S)";a*
105O IF 3*="" THEN GO TO
10&0 RETURN

RT

; RT 1

13,7;

FLRSH 1;

1040

48

SINCLAIR USER Ammo! I

— 1-

3

4000 >REM LOAD ROUTINE

401© CLS : INPUT "NRHE FILE TO B

E ENTERED " ; C S __

4020 XP LEN c*^S THEN LET CS=c*f

405© IF c*-"" THEN GO TO *0fO, # .
4.04-0 PAUSE 10; CLS PRINT

' FLfiSM l;"5ET UP TRPE
5 NEW LINE": PAUSE _

1050 PRINT " INUERSE 1,'PXLE
i C%; " ' LOADING"
4060: LORD C* DRTR *>*<*
1970 PRINT " ' *\'/'RB 1|;
3BDEP = PAUSE

4080 RETURN

RND PHE5

FILE
100

i iirini; 2

mum bounds, the computer will set
them automatically to 100 and 20 re-
spectively. The data entry routine is not
yet included on the menu. It is best to
put it in the menu routine at line 750
and set it to the Entry Subroutine at line
7Q0O. The menu display at line 1030
will have to be changed so that "EN-
TER DATA ITEM" is displayed
under "CREATE FILE",

When Those alterations have been
made, the enter routine at line 7000 can
be added to the listing.

Figures five and six show program
listings for two techniques which can be
adapted for use with the database. They
are two of many. The study of data
sorting techniques has interested aca-
demics Tor a long time and some sophis-
ticated algorithms, step-by-step
methods of solving problems, have
evolved.

Figure five shows the Bubble or
Shuttle Sort. It is fairly simple to use
but very slow when dealing with large
amounts of data. It is called the Bubble
Son because the data is sorted into a list
in ascending order with items in the
incorrect order 'bubbling' up to the top.
The data items are sorted using a
kevword, usually the first word of or
number in the item. The Bubble Sort
will take the first character in an item
and compare it to the first character of
the next data item.

You may like to change the routine to
look at the first three or fow letters of a
word. The routine can take anything up
to three minutes to sort 50 items of data.
If you are not concerned with the time
element, the routine is easy to program

and use.

In the program, line 8010 defines the
pointers being used in the routine.
Pointer pi will show the first item on
the list and p2 the one beneath it. The
variable sc will contain the number of
swaps made in one pass, When that is
zero at the end of a pass, the sort is
concluded.

Line 8020 will send control to the

swap routine if the first data item is
greater than the second. Line 8030 ad-
vances the pointers and line 8040 will
return to the menu if the sort is com-
plete. Line 8070 returns control to
make another pass of the data.

The swap routine starts at line 8080
and 8090 will swap the data items
which are in the incorrect order. Line
8100 returns control to the main sort
routine and line 8110 informs the user
that the sort is complete. The routine
can be improved by adding a line to
make the computer display a message,
such as 'SORTING', to inform the user
a sort is taking place.

The Basic listing in figure four can
be used as a base for the other sorting
leehnique known as the Shell Sort and
the line numbers which have been
modified are shown in figure six.

The Shell Sort, shown in figures six
and 7b, is slightly more complex than
the Bubble Sort but will run faster with
large amounts of data. If a relatively
small amount of data, for instance 100
items, is to be used, the Bubble Sort
will do the job just as quickly as the
Shell Sort.

For the Shell Sort the data file is split
approximately into two halves. The
pointer pi is, as with the Bubble Sort,
set to the first data item in the file. The
pointer p2 is set to the item halfway

through the data file.

The item pointed to by pi is com-
pared to all the items in the second half
of the file and swaps are made, as
before, if pi is greater than p2. When
pi has compared item one to all ot the
last half of the fde it will point to the
second item and again compare that to
the second half of the file.

The sort is finished when either pi or
p2 arrives at the last item of the file and
the sc swap counter variable is 0. That
shows that no swaps were made in the
last pass through the data and the infor-
mation in the file is in the correct order.
Both structures created by the sort
routines from figures five and six an-
il lust rated in figure seven. As I have
said previously, they are just two of
many routines and it is possible to
create several other sorts using the two
basic structures outlined.

There are many methods of searching
data and no technique is belter than
another but in the proper circumstances
one technique can be used in favour of
another. The Binary Search deal is one
of the fastest searching routines and one
of the easiest to learn.

Obviously, speed is important in any
searching routine. Someone cannot wail
For an hour for data contained in a list of
30 items to be retrieved by the com-
puter. If that were the case it would be
easier to search through a list on paper.
One method of searching a list would
simulate a person doing it by hand very
well. That is called the Serial Search-
figures eight and nine— which can take
up to half an hour to search a list of 100
names and addresses. The listing in
figures nine and 1 1 will run on the
Spectrum but multi-statement lines,
such as 2030, will have to be eliminated
for use on the ZX-81. The routines will
run without the database but if you
want to include one of them in the main
program you use lines 2000 to 2040.
The computer scan the data list, stem

Listing 3

SfiUE ROUTINE

INPUT "ENTER

TO 5010
LET JC 4 =.C 4

500© HEM

5010 CLS
= ■*; C$

5011 IE C*="" THEN GO
5030 IF LEN jC*>& THEN
I TO 5,1

S030 PRUSE 10: CL5 PR INT

"* FLfiSH 1. 'SET UP TOPE AND

5 NEU LINE": PRUSE

504-0 PRINT ' ' INVERSE lj "

: C$; ** * BEING 5RVED

5050 SRUE C* ORTR b* f J

50&0 PRINT FILE ' "

SRWED. REWIND TAPE TO

' ' "AND PRE55 NEU LINE."':
5070 UERIFY C% DflTH b % f J :

PRINT - - * ' pile *";C*;

PIED"

506S RETURN

PILE NPM

<

PRE5

PILE ' "

; c s; " '

VERIPY'-
PRUSE

GL5 :

" * UERI

bmuai i964

SINCLAIR USER Annua! 1984

49

hy item, trying to match the key, a name
or telephone number entered by the
user with the items in internal memory.
When a match is made the item will be
displayed in full on the screen.

The length of time of the process will
depend on the speed of the high-level
language, such as Basic, or the speed of
the central processor if the program is
written in machine code- The number
of items in the list to be searched will
also be a factor in the amount of time
taken by the computer.

If you are planning to use only a few
data items you could use the Serial
Search technique. The coding is simple.
Use a variable as a counter to point to
each data item in the listing in turn.
Increase the pointer by one every time
an item is compared to the user's entry
and no match is made, When the match
is made, print it to the screen.

The Binary Search is as easy to pro-
gram as the Serial Search but the rou-
tine is much faster, as it does not have to
search ever}' data item on the list. The
data must be sorted in alphabetical or
numerical order and The computer will
look at the element at the centre of the
list of data as the starting-point— figure
10— cutting the list into two halves.

If the identification keyword or num-
ber, typed- in by the user to trace an
item in a file, and the element in The file
does not match, the computer has to
continue its search. The computer will
find if the alphabetic character or num-
ber is higher or lower than the keyword
typed-in by the user. If it is lower the
computer will take the last element

examined and make that the end of the
file, cutting away The other half.

If it is higher, the computer will Take
the last examined item as the beginning
of the new, shorter file. The computer
will then find how many elements are in
the short file and divide it by two. The
number found will be The element at the
middle of the file and that is the element
looked at next by the computer.

The process continues until a match
is made. Then rhe computer will print-
out the full data item found in the file,
The whole process is shown in figure 10
and a listing of the resulting program is
shown in figure 11. The listing can be
U&ed alone with a short data entry ron-
tine or with the database which has
been discussed as an example.

The listing in figure nine includes a
shori entry routine so that you can test
the speed of the Binary -Search. Line 30
of The routine will check to see if the
keyword entered at line 25 is the same
as the element pointed to by variable L
in the data file, bl. [fit is less than the
value of the file entry, the pointer, L,
will move further up the list and if it is
greater il will move down the list.

That part of the program is executed
in lines 30, 40 and SO. The number of
the file element in L must be an integer,
so INT is used in those lines. The 0.5 at
the end of the lines mentioned must be
added to the INTeger in L to round it
up and not down, as the Sinclair ma-
chines do automatically during math-
ematical operations.

In some cases it is necessary to dis-
play every item in a data file which has

an entry which corresponds to the
keyword input by the user. That can be
done by adding an extra condition,
IF . . . THEN, staTemeni before line 40
so that if a match occurs the program
will continue to search the file in case
There are more corresponding items. If a
long file of data is to be processed and
displayed it is a good idea to introduce
paging into the display routine.

A list of data must not turn over the
end of the screen so that a 'scroll?'
message is displayed. The computer
should display the data in pages and at
the bottom of each page a message to
the user should be displayed asking
whether he wants to see more. If the
user types-in 'no' the program control
can be returned to the main menu.

The display of data is an important
facet of any program and the guidelines
apply to data output as well as data
entry. When a menu is used in a pro-
gram and is not displayed for some time
while other operations are taking place
it is important to let the user know what
other options are available at that time.
That can best be done by displaying a
band across the bottom of the screen
with the options and the 'return to main
menu' option on it.

The main point I want to stress is
that not all users arc programmers.
That may be less so now than in the
past with the advent of home comput-
ing but there are still some users who
have difficulty even getting around the
keyboard.

While it is important to know about
techniques for file processing, it is more

Figure 41

10 REM fiPDlTlONRL POINTER RRRfl
V "C'UfiRlfiBLE p- POINTS TO NEXT

RURILRBLE SPACE FOR DflTfi.

100 DIM b* I 100 , £0> DIM C (3) : L

rr p =1
5000 REM
5310 Ct_S
ITEH3 IN
^020 LET
b030 CL5

CRERTE FILE

: INPUT "HOU MANY DRTR

FILE"? " , d$

d -URL d ft

INPUT "UIHRT 15 THE MR

XIMUM LENGTH OF ERCM ITEM ,e*

LET 6=URL ft*: IF fi>20 THEN LET

bS td j-fi)

r *

1 TO

€ ~30
&O40 DIM

T c (3> -e
9050 PRINT
ER OF ITEMS
; ' - "DKRY?"
sees I**PUT
&e?& if r*i

O 6000

5BS0 RETURN

7eaa rem drtr ENTRY

701B IF Pid THEN GO
7020 INPUT
b$=" 5TOP "
7030 IF LEN

TO 7«6g>
7B40 LET b*
7B50 GO TO
7060 PRINT "ENTRY
MTER."*: GO TO 10
70-70 PRINT "CURRENT
GO TO L
'08O RETURN

LET t fSJ =d

LE

IHUER5E l; "MUHB
LENGTH " ,C

il«"f>" THEN GO T

S000 REH BUBBLE SORT

■5O10 LET PJ=1: LET p£=2: LET =C =

=t0£0 IF bftiplJ (1 TO 1) JbJi'P^J (1

TO 1) VHEN GO SUB B090

5<?30 LET Pi=p£: LET P2=P? + I

a©40 IF SC=0 AND p£>P THEN GO TO

3tfE%0 IF p£,ip THEN GO TO £020

S0B0 IF *e=0 AND P2>P THEN GO TO

90

507O L-0 TO B030

3030 LET SC-SC+1

9090 LET h4=b*ipl» : LET bjipi>=b
itp2.i . LET bf ipgl=hj

3100 SETUttN

a 110 C-LS : PRINT "5DRTEP" : PRUSE

3120 RETURN

ROUTINE
TO 7070

ENTER ITEH "1 b*

THEN RETURN

b*>LEN b$ IpJ THEN

tpi abj; LET p=p+l

IF
GO

t

TOO LONG. RE-E

FILE FULL

Htgure S

S**00 REM 5HELL z>ORT .

HOD IF ICRTION& TO FIGURE

ONE -
3010 LET Pl=l LET p2=lNT Ip.'S*:

LET ^ C =0
3030 IF F2>P TH£^ RETURN

50

SINCIjMR USER ArtHtmt JS

BUBBLE SORT STRUCTUREJBKFORE SORT)

-#■

H ITEM NUMBER DATA ELEMENT

1

SINCLAIR

2

MICRODRIVE
PRINTER

Figure 7b

SHELL SORT STRUCTURE (BEFORE SORT)

ITEM NUMBER DATA ELEMENT

USER

1*|RST ITEM IN FILE

HELPLINE

L>

MOUHM 1 SECOND ITEM IN FILE

important to know about the user inter-
face, Le. s bow the user will interact with
the computer and how he will cope with
your program. Once you can see the
Ukely reaction of the user and fit the
program around your intended user,
everything else will seem simple.

Now 1 want to take you back to show
how a program is constructed in a series
of numbered steps. To be gin t however,
I want to discuss errors which can occur
in programs, commonly called bugs,
and how to rid yourself of them.

Much has been written about bugs.
The term is derived from the early days
of computing when only large main-
frame computers existed. They had to
be, and still are, kept in specially-pro-
tected areas where dust or insects could
not enter the machinery. If computers

It is not important that you know
how it works but for those who are
interested the PPC system variable is
PEEKed and the current line number

locate and correct the error.

When talking about these techniques
and correcting errors* I must stress
again that they will be of help only if
you have used the structuring tech-
niques which have been explained-

I have detailed the pathway to struc-
tured programming as a series of struc-
tured steps:

First: Decide what type of program
you want and what you want it to do. It
is best to write it as a series of state-
ments in plain English,

Second: Decide how you are to
handle the task and whether it can be
done with your machine and with the
level of experience you have.

Third: Break the task into a series of
headings and sub-headings. For
example) most programs need some
form of instructive display— an entry
procedure, a calculation procedure and
an output procedure. They must be tai-
lored to meet your needs.

Fourth: Draw a flowchart. That
should take a long time in many cases.

returned from the two addresses

accessed by the statement. The instruc- It is a good idea to draw several charts,

tion to be appended to program lines is expanding the most important boxes ui

PRINT PEEK 23621 +256*PEEK the main one. In that way you will know

(23621 + 1).

That instruction can be put any-
where any number of times , It is best to
append it to the end of lines.

It is also possible to chart the course
of FOR . . . NEXT loops. It is done by
printing the variable used in the loop.
The print statement should be put at
the end of the FOR . . . statement and
not at the end of the NEXT statement.
If you do the latter the count printed
will be incorrect. Both techniques are

Figitr* &

SEARCH KEYWORD: Sind#ir

STAGE ONE:

MsfTtary aid

Read Only Memory

Sinclair Research

STAGE TWO:

were not kept clean and serviced they illustrated in diagram A-for GOTOs

could often crash and data and pro-
grams could be lost.

Most of the bugs encountered by
programmers occur because program
structure is incorrect. The statements
causing the crashes are usually the
FOR . . . THEN and GOTO lines.

When a program crashes, look at I he
report code shown on the bottom of the
screen and find the line number where
the computer ceased the RUN. A
GOTO effect should be limited to one
routine. If an error occurs at a certain
line you have to look at that routine

On some computers the system offers
a command which prints-out the line
oumber to which the computer goes
during operation. It is called the TRace
ON (TRON) routine. It can be simu-
lated on a Spectrum if you wish to add
an extra instruction to each of the
troublesome lines. That instruction will
make the computer print-out each line
number as it is executed.

and-B for FOR . . . NEXT.

The two techniques can be incorpor-
ated together in a program and, with the
error message you get when the pro-
gram crashes you should be able to

Memory aid

ftaad Only Memory

Sinclair Reaaarch

STAGE THREE:

Memory aid

Road Only Memory

Sinclair Research

SEARCH COMPLETED

UP C

PILE
C

KEYWOR

Figure 8

£000 DIM b*t!0,,±2J: R£H SET
XRMPLE DRTtf FILE
5010 FOR *=1 TO 10
20H0 INPUT b*f*J: REH

SSSTnEXT |r SgWfkT&S ENTRY
204-0 INPUT 3*: REM SEARCH

%n*n t ETT a=l REM a=NUMBER OF FI

^ELEMENT BEING "gTCHEg

2B6B PRINT BT 10,1»> FLBSH I, SE

aSSS^IF^*^ (1 TO LEN aS)=a* TH
21iS T c[s UND PRINT°St 12,0, FL.R5H

??»Stem locSted"; flash 0,b*<»>.

STOP ,^^__^__

SI

SINCLAIR USER Annual I9S4

SEARCH KEYWORD: Sinclair

STAGE ONE:

STAGE TWO;

Alphabet

Bubble

Memory

Research

Sinclair

ZX-8t

Alphabet

Bubble

Memory

Research

Sinclair

ZX n

STAGE THREE;

Alphabet

Bubble

Memory

Research

Sinclair

ZX-81

SEARCH COMPLETED

the concepts of the program before you
begin coding, [f flowcharting does noth-
ing else it will concentrate your mind on
what you want to do.

A word of warning to pcole who have
taken flowcharting to their hearts. The
technique is a means to an end and is
not an end in itself. If you think a
certain number of charts is necessary>
draw them, but do not draw charts for
the sake of doing so, because you will
often be confused as a result .

Fifth: Coding the program. The
code, in this case using the Sinclair
Basic language, should be laid out in
separate modules. The control module
should be put at the top^ as it is the part
of the program which will be used most.
Each module should be complete and
GOTO statements should be local to a
module if possible.

Sixth: In long programs* bugs, or
errors, are liable To occur frequently.
Bugs occur usually in the data entry
parts of the program and in the flow
structure- Flowcharting and structured
programming will not dispose of all
bugs but it will eliminate a few.

Now you should be able to write
reasonably complicated programs. As I
have stressed, there are two factors
which are important, more so than some
of the others, which are necessary to-
make programming easier and more
enjoyable.

The first is structure. If your pro-
gram is well-structured it will contain
fewer bugs and will, in most cases, run
faster. The second point is that the
program must be designed for ease of
use, so that it can be used by someone
who knows nothing about computers.

If you have taken my advice, or even
modified it using your own techniques,
you are on the way to being an efficient
programmer. You will And that you can
do more and programming will become
less of a difficult task and more reward-
ing-

Hnurc It

500E DIM b$i 15,3.2)

xRHPLE DRTft FILE
2Z1& FOX K=i TO IB
2025 INPUT b*tx). REM

125§ Y NEXT K-- PRINT "FILE

£0*0 INPUT a*: REM SERR^I

Ws0 LET L=INT (5/2J+0
£0B0 IF b*Ct> ti TO LEN
Ett PRINT FLPSH 1;"ITEM

2073 IF b*Cl> VI TO LEN
= N LET l=INT ClS8*+p&g
SSoB IF fe*fO i± TO LEN

EN LET L-INT Ct#aJ+ff-3
20a0 150 TD 2060

REM SET UP E

I>RTR FILE

ENTRY C
KEY WOR

5

a$s =a* th

LOCRTE& "

a** >a*

a$) i ft 9

TM

TH

Diagram A

10 PRINT PRINT PEEK 23631+25

20 PRINT PEEK £Sd21+255d*PEEK
i 23621 +D GO TO 10

Diagram B

10 FOR K=l
20 PRINT
30 N£XT K

TO 10: PRINT K

Quarts

into

pints

* S MANY of the thousands of
/A ZX-81 owners will know, the IK
.A. .L memory provided in the basic
machine is often insufficient for even
the simplest of programs. That can
leave the user frustrated as he thinks of
the program he could have writen had
he bought a 16K RAM pack. Therefore
any bytes of memory which can be
saved in a program are of great import-

ance

There arc many ways in which vital
bytes can be saved on a IK machine.
Once mastered, the user will discover
that his compter is very versatile.

The ZX-81 IK- 1,024 byws-of
memory is filled with 124 bytes used by
the machine as its system variables; x
bytes for the program; y bytes for the
display file— varies depending on how
much is printed— and finally * bytes tor
the variables defined during the pro-
gram.

Each line in a ZX-81 program takes
five bytes as soon as it is entered— two
bytes for the line number, two more fix
the length of line, and one byte at the
end for the NRWLINE. Anything
typed in the line will take up more
bytes. Thus REM statements should be
removed as a needless waste of memory,
as they serve no useful purpose except
in a machine code program.

More memory can be saved by mak-
ing one line our of two. Thus:
10 LET G - 15

20 IF INKEYS = "5" THEN LET
C = C — I

30 IF INKEYS - "8" THEN LET
G = G + 1
40 GOTO 20
can be replaced by
10 LET G - 15

20 LET G = G + {INKEYS = "8") -
(INKEYS = "5")
30 GOTO 20

The removing of one line saves the
five bytes which are taken up by each
iine and because of that saving the
program will RUN considerably faster,
The method shown, making two IN-
KEYS lines into one, is a type of condi-
tional statement similar to IF. The
condition inside the brackets can either

SIM [..-\|p USER Amtuall

52

10 LET G = 15

20 LET G = G - (1NKEY$ = "5

AND G > 0) + {INKEYS - "8" and

G < 30)

30 GOTO 20

Probably the most effective and
possibly the simplest method of saving
memory is by the use of constants
which are non-varying variables. First,
you define a variable, e.g., 10 LET N ■
a number used more than twice in the
program, at the start of the program and
wherever that number appears in the
program substitute it with the variable.

As proof of its effectiveness > 0.9K
was saved in a 16K program by the use
of only one constant— zero

Lf the number is betweeen and 255,
the function CODE can be used:
10 LET T = 14
can be replaced by:

10 LET T = CODE ":"

That will save four bytes of memory.
This method will be effective for those
numbers which have a character as-
signed to them but will not work for
those numbers 67 to 127, as they are not
used in the ZX-81 character set.

The second method is for those num-
bers above 255 or between 67 and 127,

1 1 makes use of the function VAL, thus:
10 LET V - 300

would become

10 LET V -" VAL "300"

S P ™"u^ » rod The use of VAL wH, mm *m >*» *

be correct or incorrect. If it is correct

ihe result of the brackets will be 1 but if

i: is incorrect the result of the brackets

will be 0. Therefore if the user were

pressing "8", the result of the first

bracket would be I and the second

would be 0- Under those circumstances

G would increase by one. An expansion

of the system is shown in the following

two programs:

Original

10 LET G - 15

20 IF INKEYS - "5" THEN LET

r — c — l

30 IF INKEYS = "8" THEN LET

f, ^ _| I

40 IF G < THEN LET G =
50 IF G > 30 THEN LET G = 30
60 GOTO 2d
After revision

as follows:

Numixr as it
appears in
(hsr program

lorttiining Byre

1 26-(7Fricx)

I ..HIT IIUMl^d

storage 111" l he number l*n

H2

33.0.0.0

When using a variable the nu mber will

'The removing of

one line saves five

bytes'

^^^^^^^^^^^^ ^^^^^^^^^^^^^^™

take up only one byte of memory. Con-
stants will save memory only if the
number h used three times or more in
the program-

If, however, there is a number in a
program which is used only once or
twice there are two more relatively effi-
cient methods of saving memory in this.

memory.

Numbers above 999 which can be
written easily in scientific notation
should be written in scientific notation
in conjunction with VAL, which will
save even more memory— 10,000 can
become VAL "10000" which can be-
come shortened even further to VAL
"IE4" which saves another two bytes.
After all those methods have been
employed there are still a few mow
ways of finding Lhose extra bytes. A
can be replaced by NOT Pi. That takes
up two bytes and saves five bytes over
the seven-byte number zero, A "1" can
be replaced by SGN PI, That uses only
two bytes and saves five bytes over the
seven-byte number one. A "3" can be
replaced by using INT PL which also
saves five bytes.

Galasians is a simple IK invaders
program which makes use of the whole

2 LET R-CODE " + '

3 LET N"NQT PI

4 LET U-VAL "2"
5-LET W-3GN PI

■5 I! >

'?«

H*< VflL
H-N
S-N
P-CODE

Y-R
X-RND*R

S>VRL "lE3" THEN LET

£ DIM
10 LET
20 LET
30 LET
40 LET
50 LET
£0 LET
70 IF
"C<9* '9? 1 9t>"
00- IF 3>VflL

"wc«t' i iT [ <*« y*

90 IF RND>VF(L

100 FOR T*U TO R-W
110 LET P-P-K I NKEY*«"U M
e)-(INKEYt*"5 r ' RND P>N)
U9-CLS

120 PRINT RT T,X;fWU TO luRT Y
,P+Wj" ! "ifiT RiPj"<M'96'«u5"

130 IF Y>T CJR RBS <P-W»-U THEN
GOTO VRL "140"

131 PRINT RT T,X;"-»-"jRT T.XjC

ODE R*jCHR» N

132 LET S-S+CQOE R*
133-GQTO CODE "C"

-T THEN LET V

-R
STR«

R»"

N OR
<X+RND*3-U-tX>2B>

"2E3" THEN LET A*'

9" THEN LET R*

140 IF ¥<

im LET Y

Y<R>

160 LET Y*INT

+< S<W •> )
170 NEXT T

200 IF H<S THEN INPUT H»
210-IF H<S THEN LET H-S
220 PRINT RT R,Pj"X*X"jRT

N,N,

SJ

RND P<

->

SCORE
230 INPUT
240 CLS
250 IF R* 1

1 HI
R*

j Hi" BY ";H*

.!■ ii

THEN GOTO CODE

53

SINCLAIR USER Annual

screen area. There are four types of
invaders — on-screen display of base,
missile and alien plus store, highest
score and highest scorer's name. All
I hose superb features are achieved by
some powerful memory-saving pro-
gramming.

The features to note in the LISTING
are the absence of REM statements, as
few numbers used as possible and the
use of four constants. Conditional
brackets are also put to their fullest use.
Four constants are used— R, N, U
and W which are set in lines 2 to 5.
They are followed by the variables HS,
H, S, P, X, Y and A$ in lines 6 to 90.
The FOR-NEXT loop T is used to
move the invader down the screen.
That is the most effective way of doing
it.

Line 1 10 is the INKEY$ line which
controls the movement of the missile
base. That makes the fullest use of
conditional brackets. Note that the
AND inside the brackets stops the base
from moving oft" either side of the
screen.

In line 120 everything to be displayed
is printed, for three reasons— memory is
saved as all the printing is done in the
one linej everything is displayed speed-
ily and that leads to little flicker after
the CLS in line 119,

Line 130 tests to find whether an
alien has been hit. Line 140 resets the
missile when necessary. Line 150 moves
the missile upwards. Line 160 moves
the alien horizontally to either side at
random.

Lines 200 to 250 are used at the end
of the game. Note that the CLS in line
240 empties the display, thus leaving
sufficient memory for the initilisation
routine in lines 20 through to 90, i.e.,
memory is saved here by adding an
extra line to the program.

To play Galaxians first RUN the
program. Alien after alien will dive
towards you. Use keys "5" and "8" to
manoeuvre your base. Key "0" to fire.
You cannot move and fire at the same
time due to the basic rNKEYS. As your
score increases the type of invader will
change. The random invader scores a
bonus of 200 points.

At the end of the game if the score
does not appear bur instead an INPUT
prompt appears that means you have set
a new highest score and the computer is
waiting for you to INPUT your initials
of up to five characters. Once the score
has appeared, press NEWLINE for
another game; any other INPUT will
end the game. In that eventuality
GOTO 20 will start the game once
more with the highest score retained.

Two into one will
now go on ZX-81

Merging programs is made possible

ONE PROBLEM until now with
the ZX-81 has been that when a
program is loaded from tape any
previous program in the computer is
NEWed and lost. That means that two
programs, each saved separately on
tape, could not be merged into one
program. That would clearly be useful
for, say, writing subroutines which
could be written and tested separately
and then merged with a main program
on a different tape. The merge feature
has been included on the Spectrum and
the routine we developed means that
now two programs can quickly be com-
bined into one, with few restrictions on
[he progframs so merged, on the ZX-81.
The procedure used is outlined and
explanations of the important steps are
given. The basic theory is to reserve
space in the 16K memory by putting
RAMTOP, the address of the first byte,
above the Basic system area, to a value
below the normal 16K value of 32768,
and then transferring the first program,
byte by byte, into the reserved space.

The second program is then entered,
along with a routine which will retrieve
the first program, add it to the second
program, and correct the values of line
lengths— the third and fourth bytes in
each program line, see page 171 of the
ZX-81 manual— and so on, so that the
program will not crash or behave abnor-
mally. Here is the procedure:

First, the user's first program is en-
tered from cassette tape. Restrictions on
the program are that the line numbers
must all be lower than 9899 but greater
than the greatest line number of the
user's second program, yet to be loaded.
That is so that when the two programs
are merged eventually, the line numbers
will be in the correct order and the
computer will not crash. To this pro-
gram must then be added the final line:
XXXX REM END
where XXXX is the line number, which
must be big enough to make it the last
line of the first program but must still
be less than 99. When the program is
entered, the following direct commands
must be entered^ in the correct order:
LETX - PEEK 16396 + 256*PEEK
16397 - I

LET Y = 49230 - X
PRINT Y

and the value of Y should be written or

remembered. Then:

POKE 16388, Y - 256*INT(Y/256)

POKE 16389, INT(Y/256).

X, the value of D FILE— see chapter

27 of the ZX-81 manual— minus one, is

the last byte of the program and is thus

the last byte which must be transferred.

Y is the location where the first byte of

the program will be stored— 49230 was

chosen as it leaves a little spare room

before the end of the computer's IGK;

and RAMTOP is poked to the value—

the two POKE commands— so that

when NEW is executed the transferred

bytes will not be erased. That can be

verified by tvping;

PRINT PEEK 16388 + 256*PEEK

16389

which should give the value of Y which

was written.

Next the routine given in listing one,

lines 9900 to 9920, is added to the first

program, Then type:

GOTO 9900 followed by:

NEW as soon as the computer has
finished the loop starting in line
9900.
Thar routine copies the bytes of the

first program into the memory, starting
at the location given by the variable Y.

NEW is executed to clear everything
except those stored bytes. To verity that
the first program is still stored above
RAMTOP, type:

PRINT PEEK (your value of Y)*256 +
PEEK (your value of Y + 1).

That should return with the first line
number of your first program.

The next stage is to load your second
program from tape. The program
should have all of its line numbers
greater than 13 but smaller than the
smallest line number in the first pro-
gram, so that, again, the eventual lines
when merged will be in the correct
order. Once that is done the routine
given in listing two— lines 1 to 13
only— should be typed-in, and then the
following direct commands:

Listing 1.

9900 FOR F= 16509 TO X
9910 POKE YT6509+F,PEEK F
9920 NEXT F

54

SINCLAIR USER Annual M

LET Y" (your previous value of Y)
LETK - PEEK 16396 + 256*PEEK
16397

and after those, REM statements must
be typed-in, as lines 9900 and 9901 in
listing two. Each REM statement
should include 100 Xs and there should
be 10 such REM statements for each
IK of the first program which has
already been copied above RAMTOP.
After one REM statement has been
typed-in, the other can be duplicated
quickly by using the EDIT facility and
adding 1 to the line number each time
the line is copied, In that manner the
correct number of REM statements can
be produced quickly.

As soon as the REM lines have been
typed-in, the command GOTO 1
should be entered. The routine— lines 1
to 13— will then transfer the first pro-
gram back from above RAMTOP back
to the main program, and when the
report code 9/13— STOP executed in
line 13— is seen, the final. The merged
program can be tidied by deleting lines
I to 13 and any left-over REM lines
after line 9900 may also be removed.

This is how the final 13-line routine
works:

The first two lines POKE RAMTOP
to its usual (16K) value of 32766. That
is so that as the routine progresses, the
space where the first lines were stored
can be overwritten once those lines
have been rc-transferred, and that en-
ables longer programs to be merged.

Lines 3 to 4 check for the location of
ihe REM command in the line:
XXXX REM END

at the end of the first program, that
being the marker used to indicate the
end of the first program, and the loop
passes to line 5 with the variable F
being the location of this REM com-
mand. The variable K which was de-
fined previously by direct command is
the location of the first byte in the first
RE\t line— line 9900— and is the loca-
tion into which the first byte of the first
program is POKEd. The REM state-
ments are used to reserve space below
the Display File— we spent some time
trying to POKE the system variable D
FILE but with no success— and the first
program is simply POKE into the loca^
tions occupied by the REM lines. Thus
lines 5 to 8 POKE the first program
into the space reserved by the REM
lines, except for the CHR$ 118 which
indicates the last character in the line:
XXXX REM END

Lines 7 and 9 are to clear the space
which was occupied by the first pro-
gram. Finally, lines 10 and 1 1 count the
extra Xs left over from the last REM

REM

END

line POKEd into and line 12 POKEs

the new length of the last line into the

appropriate location. That means that

the line

XXXX REM END

will finally become:

XXXX REM END (+ left-over Xs

from the REM line)

e.g., XXXX

xxxxxxxxxxxxx

and the appearance of this is an indi-
cation that the merging is successful. Of
course, if the final REM line had exact-
ly the correct number of Xs, the line
will remain
XXXX REM END

Using this routine we believe that
any two Basic programs can be merged
into one. Of course, that does not ex-
tend the limit of 16K imposed by hav-
ing only a 16K RAM pack and it should
be noted that any variables stored will
be lost as the procedure is followed.

A large number of direct commands
have been used where they could have
been included in the two routines we
have given— listing one and two— since
if the procedure is to be worthwhile it
should be as short as possible.

For long programs it is obviously
superior to run the two routines in
FAST mode but that is not very infor-
mative if for any reason the computer
should crash. Therefore until you are
confident that you have the procedure
correct, we suggest that you take the
extra time to run the routines in SLOW
mode and keep an eye on the computer,
even if that takes a long time.

Listing 2.

1 POKE 16388,0

2 POKE 16389,128

3 FOR F = Y TO 99999

I IF PEEK F<>234 OR PEEK
(F+])<>42 OR PEEK(F + 2)<>5I
OR PEEK (F+3)<>4J OR PEEK
(F+4)< > 118 THEN NEXT F

5 FORO = Y to F+3

6 POKH G + K-Y,PEEK G

7 POKE G,0

8 NEXT G

9 POKE G,0

10 FOR G = F + K-Y + 4 to 99999

I I IF PEEK G <> 1 18 THEN NEXT
G

12 POKE F + K-Y-2, PEEK
(F + K-Y-2)(F + G-K + Y-4
H STOP

9900 REM XXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXX
XXXXXXXXXXXXXXXXXXXXX
XXXXXX XXX XXXXXXXX XX XX
XXXXXXXXXXXXXXXXXXXXX
X

9901 REM (100 Xs)

10 lines per IK stored program

Chess is
in check

Chris Whittington

BROADLY, there are two main
schools of thought concerning
the problem of programming
computers to play a game such as chess.
The first and most dominant suggests
that ihe way forward is to use the
number-crunching power and speed of
modern computers to plough their way
through as many possible paths arising
from a particular position, apply some
simple evaluation to the positions aris-
ing in the path, and by that method
arrive at the best move. That approach
has become known as the brute force
method.

The second school of thought points
to the highly-successful techniques al-
ready applied by human players to the
problem and suggests that the best ap-
proach would be to teach the computer
to think like the best human players.
We shall call this the knowledge
method.

Faced with the problem of producing
an effective chess-playing program for a
home computer such as the Spectrum,
we can probably discard the knowledge
method, ironly because we still have no
real idea how it is thai human grand
masters decide on their next best move.
Indeed, what do we mean by best move?
There is no real choice at present other
than to use the brute-force method Tor
solving the problem.

Before we begin to explore a possible
solution it would be best to examine in
some detail the nature of the problem.
Chess is a two-player game.

Whatever is good for one side is bad
for the other and vice versa; such games
uc known as 'zero-sum games*. That
will allow us to make statements such as
this move gives White a score of +250
and thus gives Black a score of -250.

The |ame is played on a board of
fixed size with a fixed number of pieces;
therefore we should be able to represent
the board and pieces in some way in the
computer memory.

The laws of chess define how ihe
pieces move, whether any position is
illegal — for example, leaving one's king
in check— and how to decide on wins,
losses and draws. In principle, there-
fore, we should be able to define and

SINCLAIR USER Anna*! 1984

55

encode all the possible ways of moving a
chess piece, detecting checks and so on.
Unfortunately) from our point of
view, a number of different chess pieces
each move in a different manner and
some of them move in some different
manner in special circumstances— for
example castling, en passanL

I suspect that the apparently daunt-
ing task of defining all those possible
moves for each of the pieces and encod-
ing them into assembly language deters
many a budding chess programmer
from beginning the task.

Some of the early chess programs,
and even some one can still buy, avoid-
ed the problem by not implementing
The difficult portions, with the result
that their program just never did castle
or capture en passant.

The problem is not as daunting as it
seems ; one can work out routines to do
the task and theTe are published algo-
rithms, and even listings^ which can
remove some of the tedium.

Since we have to decide on a best
move we will need some way to evalu-
ate, or attach a number to, any move.
The conventional wisdom is to keep
that position evaluator as simple as
possible, usually measuring the balance
of material and a few positional factors.
It will be of interest to note that the
positional evaluation will be the only
part of the program where chess knowl-
edge and skill, as apart from a knowl-
edge of the rules of the game, will be
required,

There has been much controversy
between strong chess players and com-

*We must concentrate

on refining our

search through the

tree of moves'

puter programmers as to whether poor
chess players can produce good chess
programs.

Certainly the best programs usually
have been prepared with the help of
strong players and my feeling is that
substantial chess knowledge is of most
use after the program has been complet-
ed and is being play-tested to tweak the
program to its optimal performance by
adjusting the evaluation function.

Then we have the problem of how to
plough our way through all the moves
to arrive at our brute- force solution. In
chess programmers' parlance that is
known as the 'exponential explosion
problem* and it goes something like

this:

On the Spectrum we can evaluate a
position in, say, 25 milliseconds. In any
one chess position there will be around
30 legal moves to consider. Thus to look
one half-move deep we need to evaluate
some 30 positions to arrive at the best
move. That takes 30 times 25 millisec-
onds, or 0.75 seconds.

To search two-ply deep we need to
look at 30 positions and all the 30
positions arising from each of those— 30
times 30 positions in all will take 900
times 25 milliseconds or 18 seconds.

By that reckoning to search three-ply
takes nine minutes, four-ply takes 4,5
hours, five-ply takes almost a week, and
so on.

To achieve good results against
strong players, a program will need to
search between eight- to 10-ply moves

deep. According to the previous calcula-
tions an eight-ply search would take 400
years to complete. Such a game, starting
in pre-history might now be nearing
completion.

If we are to get anywhere using brute-
force methods we must concentrate on
refining our search through the tree of
moves to reduce or eliminate the blow-
up effect , As an aside, a game such as
draughts, which has far fewer possible
moves arising from any one position,

does not generate such severe problems
and thus machine-coded draughts pro-
grams are more likely to defeat strong
players than similarly-encoded chess
programs.

Fortunately there are several methods
to refine the tree search. The programs
available on the Spectrum and ZX 81
have reduced the multiplication factor
Tor each ply from about 30 times to
around four to eight times.

Adopting a top-down approach to the
problem, we can formulate our first
statement of the approach we shall be
taking.

We shall use the method of brute
force with refinements, evaluating each
node— position— in the tree of moves
according to a simple and fast evalua-
tion function, biased heavily by material
factors.

The program will need to be as fast as
possible and must therefore be encoded
into machine code. Baste would be far
too slow r

We shall require adequate tools Tor
this task. As a minimum we shall need a
powerful editor to work on the assembly
language files. Since those files may be
as large as 40K bytes- 10OK bytes
when properly documented— we shall
need a disc-based system to hold ihem.
We shall need an assembler program
to turn the assembly language files into
machine code and a monitor program to
help remove bugs.

Only after the program is running
without bugs shall we consider putting
it on to our small home computer sys-
tem.

Our next task will be to break down
the problem further and define particu-
lar areas of the program to which we
must attend.

Main modules— tree-search algo-
rithm; move generator; is king in check?
detector; position evaluator.

Database— how to represent the
chessboard; how to store the moves and
positions as we move up and down the
tree; tables containing knowledge about
the position which can be used by the
position evaluator.

REFERENCES

Chess skifi in man and machine. Editor, Peter
Frey. Pubtwher, Springer Verglag.
Sargon, a computer chess program. Au
thors, Dan and Kathtf Spracklen. Publisher,
Haytfen.

The machine pfays chess? Author . Ale* Bell.
Publisher, Pergammon.

Think like a grand master. Author, Alex-
ander Kotqv. Publisher. Batsford.

56

SINCLAIR USER Annwi 1984

^

Putting brains
into monsters

Donald Hughes writes adventures

HOW MANY TIMES have you
wished you could write adven-
ture programs? How many
times have you started, only to cease an
hour later, frustrated by the awful com-
plexity? If the answer to the second
question is too many times, you are
probably approaching the problem from
the wrong end.

An adventure game should be split
into two parts— the brain and the adven-
ture. "

The brain is the interactive pan of
the program which communicates with
the adventurer, answers queries^ picks
up items and drops them. The adven-
ture can then be rendered into data
suitable for the brain.

The brain is a loop, normally large,
which uses 9 READ statement to take
data for the adventure from successive
DATA statements. Normally the brain
program will run its course once per
adventure location, so when a location
is left, it draws new data from the
adventure. Using such a brain, each
adventure location can be stored in one
DATA statement of set format.

You must start by deciding what

initial intelligence the brain will have. I
recommend you do not aim for any-
thing more intelligent than the simple
example. The example brain under-
stands only one word at a time and they
must be keywords. If the command
given is not a keyword, the brain is so
unreceptive that it proceeds merrily
along as if it had found a keyword. It

'Do not expect your

first brain to run

adventures of a

professional standard'

works, though, and you can write ad-
ventures, using the brain, in two hours .
Starting with a brain similar to the
example, you can add keywords slowly
until it is reasonably intelligent, and
you can have complex adventures, but
start simply, or you will find yourself
trying to debug a program which does
not work far enough for you to find the
bugs, let alone see what is not correct;
and it will be back to the frustrations.

Do not expect your first brain, or the
example, to run adventures of a pro-
fessional standard; that is not the aim—
it is to let anyone starting on a Spec-
trum have fun with programs they
thought were only in the realm of
professionals.

A simple brain operates in this way.
The text of the first location is read in;
the number or items in a room is read
in; the items in the room are read into a
string array, then printed-out along
with a copy of the text; the monster in
the room is read in, along with its
strength. Logically, before the player
may take an item he must defeat the
monster. Once the monster is dead, the
brain asks what function is required.
The functions understood are;
Take— to pick up an item,
Drop— to drop an item
Invc — produces an inventory.
Leave— leaves the room.

Those instructions, combined with
an imaginative adventure, are sufficient
to entertain,

SCORE SHEET

Due to ihc limitations of the brain,

htre Is how to score your performance in
this adventure:

II vdii cheated with ihc pries ti, 0: if y uu
took the heavenly hcinp, 0; if you died, 0.

You should have wilh you a sword, t>a£
of coins, Fkjx of coins, ruby and Spec-
trum — the mosl valuable item.

If you have all five, excellent; only
four, good; only three, fair; only two,
bad; only otie — have you not pUyed *n
adventure pmt previously? 1

LET s-350

DIM v* f to, 10 '

ze let n«*

95 REM fc-isic first ^i«M
CLS
READ t«

IF t*-"wr.d" THEH CO TO 9900
110 PPINT t*
120 PRINT "IN THIS

10
15

97

100
:2Z

ROOM THERE I

130 READ re
133 DIM i*( re. 40>
140 FOR T*l TO re
150 READ ««* •

169 PPINT j*f q J

170 NEXT q

180 REM Montttr*

190 RERD in*-*

195 IF tt*-"neme'* THEN GO TO 263

230 PRINT "YOU SEE A "'mfi","
00 YOU WISH TO FIGHT-'PUN CrVftJ"

210 INPUT u*

220MF u«-'"f" THEN CO TO 430

230 IF u*-"r" THEN PPINT "BY WH
1CH EXIT 00 VOU WISH TO MFIKE YOU
R ESCAPE"

240 INPUT e»

250 GO TO 430

250 PEN r«tum fro*fittrit

£70 PRINT "YOU MAY NOW TAKE OP
PROP P.N ITEM OP YOU MAV LEAVE"

200 INPUT c*

290 IF e*""t*k»" THEN CO TO 570

IF ^■-"■"JrOF-"

IF c*^"lojve

THEN CO TO 620
1 THEN GO TO 41

IN WHICH DIRECTION"

rS

300

315

320 IF ct^MflV*" THEN GO TO 820

330 PRINT "USE COMMANDS TRKE D
POP. I NVE, LEAVE"

340 CO TCI iOO

400 REM

410 PPINT

420 INPUT

430 CO TO 9000

440 ■'STOP

450 REM fiflhtiTiS

460 PPINT "THE ".»i*. H HRS ";W '

STRENGTH PTS,DQ YOU STILL WISH
TO FIGHT"

471? PRINT "(Y-'N

400 INPUT f«

490 IF <■<■."*" THEN PRINT "BY U
HIGH EXIT DO YOU WISH TO MAKE YO
UP COWARDLY ESCAPE"

495 IF .f«-"v" THEN CO TO 310

500 GO TO 240

310 LET »*»-<«*< PND+i. >>

520 IF *<-0 THEN PRINT "Hfl HP, ,
VOU RPE DEAD, BYE"

325 IF s>0 THEN GO TO 340

530 GO TO 440

540 PPINT "THE "m*," IS DEAD"

330 GO TO 2*0

560 REM tikinfl

S7B PPINT "WHAT DO YOU WISH TO
TRKE"

373>LET N-K+l

580 INPUT Y*< n >

502 IF N>"5 THEN PRINT "YOU BUS
T DPOP ON ITEM BEFORE VO. HAV TR
KE AGAIN"

€00 PPINT "VOU MAY NOW CONTINUE

610
620
630

DROP'
635
£40
650
660
670
690

GO TO 270

REM drcPp in?
PRINT "UHRT DO

YOU WISH TO

DIM d*f 10 ■'
INPUT [■•
FOP C-i TO
IF d*-**'' c
NEXT

-.

THEN GO TO '10

PRINT
AN ITEM"
690 PRINT
CO TO

YOU DO NOT OWN ?UCH

"TRY RGRIH"
S38

FDR 1 z~C TO n

LET y« r>-**[ z+1 l

NEXT r

LET n»r»-l

PPINT "O.K. "

PPINT -'DO YOU WISH TO TRKE
AN ITEM f.vrrtV
760 INPUT C*

770 TF c»^>"w" THEN GO TO 'j00
760 PPINT "WHAT 7"
■790 LET n-r,+ l

INPUT »%( r> >

GO TO GOO

700
710
720

730
733
740
750

300
810

SINCLAIR r St: R Annual 1984

57

The brain then asks a question, de-
pending on the keyword used. For
example, What do you want to take?
Type-in, e.g. "sword". What do you
wish to drop? Type-in, e.g., "coin". IF

flipping through the DATA to find any
adventure location, so one can go N, S >
E, W. The example brain suffices with-
out that.

In writing adventures, first examine

4 A simple brain operates by reading in the text
of the first location; the number of items in a
room is read in; the items in the room are read
into a string array; the monster in the room is
read in, along with its strength*

you not want a monster, type-in the
DATA positions for M and S "none",

Try typing- in the adventure detailed
into your Spectrum and playing it to see
the possibilities, within the limitations
of even a simple brain. You should have
plenty of fun. After that, write your
adventure for it. Real beginners should
be very careful when typing-in the ad-
venture; a bug will make itself immedi-
ately and annoyingly apparent.

To use the brain on a ZX-SI, you will
have to circumvent the H 'who needs
READ statements" problem.

Combat works this way; your
strength is 5; monster strength is M. In
combat, this operation takes place
LET S = S-(M»(RND+ 1})
which means a random figure varying
between M and nearly M*2 is removed
from your strength in defeating the
monster. For different adventures, dif-
ferent Ss can be given, so only by
choosing carefully what to fight can you

win.

INVE was used, the brain prints-out an
inventory.

When LEAVE is typed-in, the brain
asks in which direction. That is merely
for show as, when a direction is typed-
in, it PRINTS "you are going to the
next room", PAUSES for a second;
CLEARS the screen; and RESTARTS
THE LOOP, reading in the next por-
tion of DATA.

One of the first improvements to the
brain you should make is a way of

the listing. The brain is obvious, lines
95 to 850. Remove the data statements,
1000 to 8000, Insert your own data, in
this form:

1000 DATA "A", "X", "B", "B'\
"B'\ "M", S

A is text describing the room; X is
the number of items in the room and
must be equal to the number of strings
following it; B is a string, an item in the
roctm; M is the name of the monster; S
is the strength of the monster. Should

List of variables used in the program.

TS

■ texr

re

= number of items, in a room

AS

= array of room content*

MS

= mojwer name

M

■ monster strength

tt-i

= answer to light/run option

l_jj

= command wniii

C

= used in ktops

Z

■ used in loops

s

- your strength

F|

-answer in fight routine

YS

-answer in take routine

d$

= answer in drop routine

<=*

= r.x'H direction

10 LET s-330

is dim »•< ie. tfl.'

20 LET N*-0

9"5 PEM tisic first view

97 CLS

100 READ t«

105 IF t«-"*rid" THEM CO TO 5S00

ue print t>

120 PRINT "IN THIS P0OM THERE I

130 REAC- re

133 DIM at' re, 40}

140 FOP q«-i TO c-c

150 PEAD 9*<.<t)

1 60 PP I NT tMi 4 ;>

170 NE^T q

130 PEN n^riit-rs

] 30 PE AD en* , m

195 IF ^-"none" THEM CO TO 265

200 PRINT "YOU SEE H " i l*f . " . " ' "
DO YOU UISH TO FIGHT-'RUN <F-'R>"

210 INPUT wi

220MF ui-"f" THEN CO TO 450

230 IF ul-"r" THEN RRIWT "BY WH
ICH EMIT DO YOU WISH TO MAKE YOU
P ESCAPE"

240 INPUT tf

250 CO TO 430

260 PEM r*tu.rn frofrfiflht

£70 PRINT "YOU HAY HOW TAKE OR
DROP AN ITEM DP YOU MP.V LEAVE"

290 INPUT -*

290 IF e**"**k»" THEN GO TO 570

300 IF ct-'-d^oP" THEN GO TO 620

315 IP c*-"l-iv-" THEN CO TO 41

320 IF c**"inv* n THEN GO TO 820

338 PRINT "USE COMMANDS TAKE ,D
R0P..INVE, LEAVE"

346 GO TO ?ee

400 PEM

410 PRINT "IN WHICH DIRECTION"

420 INPUT c«

430 CO TO 9000

440 >ST0P

450 REM flflhtinQ

468 PRINT "THE ";*»;" HAS " ..

STRENGTH PTS.00 YOU STILL WISH
TO FIGHT" 1

470 PRINT "(¥,'N ■'

40G INPUT f*

4S0 IF f*-- "v" THEN PRINT "BY U
HIGH EXIT DO YOU UI5H Tn nftKE YD
UP COWARD LV ESCAPE"

495 IF f*»-'a" THEN GO TO 310

309 GO TO 240

310 LET ■>«•<**( RNfr+D)

520 IF *'-0 THEN PRINT "HA HA -
VOU PRE DEAO,BYE' -

323 IF ->0 THEN GO TO 340

530 CO TO 443

540 PRINT "THE "ltiMi n IS DEAD"

353 GO TO 26*

560 REM tikinQ

570 PRINT "WHAT DO YOU WISH TO
TAKE"

375>LET N-N+l
580 INPUT Y*<«)

532 IP H>-5 THEN PRINT "YOU MUS
T DROP AN ITEM BEFORE VOU J*IAY tr
K£ ACRIN"

600 PRINT "YOU MflY NOW CONTINUE

II

610 GO TO 270

620 PEM ctrnp-p in«

£30 PRINT "UHRT DO YOU WISH TO
CROP"

635 DIM d*C 18;'

640 INPUT ['<■

650 FOR C-l TO H

£60 IF e»#-M*<c) THEN GO TO 710

670 NEXT c

600 PRINT "YOU DO NOT OWN SUCH
AN ITEM"

690 PRINT "TRY AGAIN

700 GO TO 630

710 FOP *"C TO n

720 LET i%t z )-jJ< z+l )

730 NEXT Z

735 LET n-tt-l

740 PRINT "O.K. "

739 PRINT "DO YOU WISH TO TAKE
AH ITEM Km

760 INPUT C*

770 IF c*<>"v" THEN CO TO $90

700 PRINT "WHAT T"

790 LET n-n+i

800 I NPUT tKtl)

010 GO TO £00

58

SINCLAIR USt-R Annual ?984

Sorting through memory
for some useful addresses

Dilwyn Jones explains the workings of systems variables

SYSTEM VARIABLES are the
bytes in memory from address
16384 to address 16508 in RAM
on i he ZX-S1. They are used by the
computer to remember certain things
about its workings, such as where to
print next-

You can make use of some of them in
your programs either by reading their
value— PEEKing— or replacing them
with new values— POKEing— so as to
use the information they contain or
make the computer do something it
might not otherwise do.

Not all of them can be used in this
way; some may ignore you, whereas
changing the contents of some of them
may cause strange effects, like making a
mess of the screen display. At worst, a
little nasty known as a crash may be
caused,

• 16384 ERR-NR (Error report
number). The value contained in ad-
dress 16384 determines the report code.
If you POKE a number into 16384
which is anything other than 255, the
program will stop and display an error
code, which may be non-standard but
meaningful in some way.

For example, if you wanted to ar-
range thai if the user entered an incor-
rect value the program stopped with
error U-standing for USER ERROR-
you would arrange that POKE
16384,29 was executed. To determine
which value to POKE, remember that
16384 has a value of 1 less than the
report code.

The error report code can be sup-
pressed by POKEing certain values into
this system variable. That may be use-
ful at exhibitions, where a report code
may be an unsightly distraction from
the rest of a display. Experiment with
POKEing some of these numbers into
16384: 43, 70, 72, 73, 74, 75, 76, 77, 79
81, 82, 89.

• 16386/7 ERR-SP. This system vari-
able contains the address of the first
item on the machine stack after the
GOSUB returns. With PEEKing this
two-byte system variable you can check
how many GOSUB return addresses are
present on the stack, for example to
check if any bug in your program had
been causing it repeatedly to call and
jump out of subroutines. Here is how to

check:

PRINT (PEEK 16388 + 256 x PEEK
16389MPEEK 16386 + 256 x PEEK
16387)

• 16388/9 RAMTOP, RAMTQP is
the address of the first byte of memory
above that used by Basic. NEW oper-
ates only this far, so anything placed
above RAMTOP is safe from every
Basic function except POKE— that is
how you would put it there. That makes
it ideal for storing machine code or data

you want to pass between two pro-
grams, so that it is not lost when you
execute normally-destructive com-
mands like LOAD or NEW. On a IK
ZX-81, 16388/9 have the values 1 6 388
16389 68.

Using the formula from chapter 28 of
the ZX-81 manual, + 256 * 68 is
17408. That is the normal address of
RAMTOP in a IK ZX-81. If you have a
RAM pack plugged- in and wish to see if
a program you have would fit into 1 K,
it may be tested by POKEing the fore-
going values into RAMTOP, then en-
tering the command PRINT USR
1040. The machine will behave like a

IK ZX-81.

The value contained in RAMTOP
also determines how the display file-
screen picture— is made up after CLS,
If the value in RAMTOP is less than
19712-16388 = 0, 16389 = 77-the
display file is contracted to minimum
size consisting of only 25 NEWLfNE
characters, If RAMTOP is 1 97 1 2 or
higher, the display file is expanded by
filling with spaces. A contracted display
file has the advantage that it takes five
seconds less to LOAD or SAVE pro-
grams.

• 16391/2 PPC. Contains the line
number of the statement being exe-
cuted. It could be used as an aid to
debugging a program which has com-
puted GOTOs/GOSUBs all over the
place; a few PRINT PEEK 16391 +
256 * PEEK 16392 statements here
and there could determine whether or
not the program went where you
thought it should do.

In the last line of a program it deter-
mines the line number to be printed by
the report, e.g., 0/100. You may like to
use that to print a score on the screen at
the end of a game.

« 16396/7 D-FILB. Contains the ad-
dress of the start of the display file. The
character pointed to is the first NEW-
LINE character in the display file.
Since the display file floats above the
program in memory, you can use it to
tell you where the program ends, giving
you an indication of the length of the
Basic program, since the Basic program
starts at 16509: PRINT PEEK 16396
+ 256 * PEEK 16397-16509 will tell
you the length of the program in bytes.
If you want to PEEK/POKE into the
display file for any reason, this system
variable helps you by telling you where
in memory it starts.
• 16398/9 DF-CC. Tells you where in
memory the current PRINT position
lies, PEEK 16398 + 256 * PEEK
16399 gives the address in RAM of the
current PRINT position. That could be
POKEd to change the PRINT position.
Alternatively, if you PEEKed the ad-
dress of the PRINT position, you
would obtain the CODE of the charac-
ter already at that position— useful for
detecting collisions and so on in games,
or for programs which require a screen

SINCLAIR USER Annual 1984

59

si

cursor to be highlighted in inverse video
such as word processors:
LET AS *= CHRS (PEEK {PEEK
16398 + 256 x PEEK 16399})

IF AS > "A" AND AS < = "Z"
then print at Y, X; CHRS (CODE AS
+ 128)

The statement PRINT AT Y,X;
moves the cursor without printing,

• 16400/1 VARS. This pair of system
variables enables you to find the address
of the start of the variables area if you
want to go PEEK in g or POKE in g
around, or the end of the display file if
you want to work backwards to POKE
characters on to the boitom two lines of
the display which cannot normally be
PRINTed upon.

• 1640-4/5 E-LINE. Contains the ad-
dress of the end of the variables area.
We can examine it to give a rough idea
of how much memory we have used*
including system variables, program,
display and variables:

PRINT PEEK 16404 + 256 x PEEK
16405-16384

• 16412/3 STKEND, Contains the ad-
dress of the top end of the calculator,
immediately below spare memory. Used
in conjunction with ERR-SP 16386/7,
we can obtain an approximate idea of
how much memory we have left in
which to work. PRINT (PEEK
16386— PEEK 16412} + 256 x (PEEK
16387-PEEK 16413) The figure is in
bytes.

16417 not used. This system variable
is not used but is available to the user;
you could use it to store information in
the form of an integer from To 255.
Thai would be saved on tape when the
program is saved.

#16418 DF-SZ. Define screen size, or
the number of lines in the lower part of
the screen. If you PORK a value of 1 or
into this system variable you can use
lines 22 and 23, so that PRINT AT
22,0; and PRINT AT 23,0; become
acceptable statements. If using INPUT
or SCROLL, you should restore the
original value, normally 2, or you may
cause a crash, Conversely, if you are
short of memory and using a SCROLL-
ing display, you can make scrolling start
from further up the screen by POKEing
a value greater than 2 into 16318, a
Basic part screen scroll.
• 10419/20 S-TOP. This contains the
number of the top line in automatic
listings. Automatic listings are those
produced when you press NEWLINE.
It can be annoying when you are trying
to work on one part of a listing and the
computer insists on displaying a differ-
ent part.

To place any line number you want,

say line X, at the top of auto listings you
must lirsl move the cursor to a line
number greater than the one you want
at the top. Then enter the commands;
POKE 164l9 ) X-INT(X/256) x 256
POKE I6420,rNT(X/256)
• 16425/0 NXTLIN. The address of
the start of the next program line. You
could use it to run machine code in a
REM statement anywhere in the pro-
gram, e.g.:

100 LET A - L7SR (PEEK 16425 +
256 x PEEK 16426 + 5)

101 REM . . . machine code . . ,

Or you could use NXTLIN to securi-
ty-lock lines into programs to point out
that, for example, you hold copyright to
a program. It should not be possible to
edit out those lines easily. The easiest
way of doing so is to change the line
number to 0, which cannot easily be
removed. As an example, we will lock
line 100 in the following program:

give a value in seconds: LET TIME -
(65535-PEEK 16436-256*PEEK
16437}/50

The variable TIME then contains
the time elapsed in seconds since the
frame counter was re-set.

Remember that PAUSE uses the
frame counter, so you cannot be timing
and use PAUSE, too. If you want a
delay while using the frame counter Tor
timing, use a FOR/NEXT loop of about
I to 60 for every second of delay.
Remember also that bit 15 should al-
ways be 1 when timing, If both bytes of
the frame counter reach ?.eroj the pro-
gram will crash,

• 16441/2 S-POSN, After you use
PRINT at Y,X; where Y and X are
print coordinates:
PEEK 16441 would be 33- X
PEEK 16442 would be 24- Y

16441 contains information as to the
PRINT column number but it is not

'It may be necessary to determine whether
there is room for a word on the current line or
if it is necessary to move to a new line to
prevent the word being chopped in two'

1 REM any program

2 REM 1982

90 LET A = PEEK 16425 + 256 x
PEEK 16426

100 REM (Q DILWYN JONES 1982
1 10 POKE A>0
120 POKE A + 1,0
1 30 STOP

Now edit out the additional lines 90,
1 10> 120, 130. You should be left with:

1 REM any program

2 REM 1982

RAM (C) DILWYN JONES 1 982

Note that the lines are not necessarily
in the correct order but that will not
affect listings or the running of the
program.

• 1(1436/7 Frames. This is a frame
counter which counts the frames of a
picture sent to a TV set. It is increment-
ed 50 times a second and can be used for
timing with a range of about J I minutes
before repeating. To set the timer in-
itially we use:
POKE 16437,255
POKE 16436,255

They may be entered as direct com-
mands or used as program statementSj
although of more use within programs
because of the limited timing range.
The values of the frame counter start at
65535 and count down to 32768, be-
cause bit 15 is normally 1. Once it has
been re-set, its value is read like this to

very easy to use. HX is 0— the PRINT
position is somewhere on the left-hand
side of the screen— the value of 16441
starts at 33 and decrements by 1 for
every column across the screen. The
value of 16442 starts at 24 if the
PRINT position is at the top of the
screen and decrements by one for every
line moved down the screen; 1 6441 may
be used in programs which handle text.
It may be necessary to determine
whether there is room for a word on the
current line or if it is necessary to move
to a new line to prevent the word being
chopped in two. Suppose the word to be
printed was A$. To prevent AS being
chopped in half you could use:
IF PEEK 16441 < LEN AS + I
THEN PRINT

always assuming; of course, that the
previous PRINT item ended in a semi-
colon or comma. It may help to think of
16441 as the number of characters + I
which can still be printed on this line of
the screen.

• 16444 to 16476 printer buffer . If
the printer is not used, may be used to
store information if you have nowhere
else to put it.

• I6S07/8 not used. These two un-
used system variables can be used by
the programmer to store integers if
needed. They are saved on tape along
with the program.

J

GO

SINCl^tR USER Annua! 1984

.

Inside Sinclair

Sinclair Research has always been much

more than Sir Clive Sinclair. In our

occasional series we have been behind the

scenes to find the people who help to make

the company successful.

! 1984

SINCLAIR USER Annua! !S84

61

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PEEPING from behind rows of ter-
raced houses near the centre of Cam-
bridge is the Sinclair Research ultra-
modern new computer centre.

The architect, Cristoph Grillet, pic-
tured left, of Lyster, Grillet and Har-
ding, is said to have combined
Cambridge traditions with major inno-
vations in architectural design, interior
furnishing and environmental control
systems.

One of the ducts for the system can
be seen in the picture on the immediate
left above the office which overlooks the
entrance hall. The hall is dominated by
the sculpture, shown far left, Double
Torso II by Helaine Blumenfcld.

Stainless Sinclair

,*

?
&

>\G L

P

SINCLAIR L'SER Annual 1984

6}

Former school chum now
looks after the money

In the management changes at Sinclair Research last year, Bill
Matthews became financial director. He talks to Claudia Cooke

BILL MATTHEWS sits in his
office and smiles at the recollec-
tion of his old school chum, Sir
Clive Sinclair, tinkering with radios
while the other boys listened to them.

"He was innovative even at that age,
you know. He was always tinkering
with something and he made his first
matchbox-sized radio while we were
still at school.

"We lived very near each other in
Guildford and I remember going to his
house for enthusiastic demonstrations
of his latest plans. I think he was very
much an individual character and did
not fit into the standard schoolboy im-
age at all".

A great deal has happened to both
men since those early days at St
George's School, Weybridge, Surrey.
Now, once again, they are together, BilJ
Matthews having joined Sinclair Re-
search as finance director last Septem-
ber.

"I was working in Toronto last year
and Clive had to go there for a Mensa

conference. We had lunch and he asked
me if I was interested in this job. I
thought what the hell, why not? Here I
am, thoroughly enjoying it".

The two men, in fact, worked
together previously, but in the very
early days of Sinclair Radionics. "I
think I kept his cash book or something
when he was busy packing-up and sell-
ing little bits by mail order. It seems a
long time ago".

Matthews, now 43 and married with
four children, went straight from school
to read economics and business admin-
istration at Sheffield University. He
followed that with training at a firm of
accountants in London, qualifying as a
chartered accountant in 1963.

The first five years of his career were
spent in public accounting in Turkey
and Italy, "It was great to be able to
travel and, having been released from
all that studying, I did a reasonable
amount of work but certainly nothing
you could call strenuous".

Then followed marriage and the offer

of a job with TCI as a group accountant.
He spent four years there and still
considers it one of the best -run compan-
ies for which he has worked.

He moved on to become financial
controller for Sony U.K. for two years

'He asked me if I was

interested in this job.

I thought what the

helU why not?

and was involved in setting-up the com-
pany's successful television factory in
Wales. Emigration to Canada was the
next step, working for management con-
sultants Price Waterhouse. His most
recent job, in Houston, Texas, was as
executive vice-president of a company
with clients from the oil and gas indus-
tries.

64

STNCLAJR l\SKR Annual 1984

A varied career but one which has
always involved him in the use of com-
puters, particularly for management in-
formation. The finance department at
Sinclair Research is now in the process
of computerising its system with an
ICL 25. Matthews expects it to be of
considerable help in financial reporting
and control.

One of his first tasks at Sinclair was
to place 10 percent of the company
shares with institutional investors* an
offer which was well-subscribed. He

says;

"We see ourselves getting a Stock
Exchange quotation in two years. It is
still our intention to keep the company
small in terms of (he number of people
employed; that concept has not disap-
peared.

"Sales have grown substantially and
we have reached a size where we could
issue shares and get a public quotation.
It will be our coming of age, if you

like".

Matthews sees one of his tasks as
ensuring that Sinclair has sufficient re-
sources to continue to grow rapidly and

'We have to be

careful because the

life expectancy of our

product is fairly

short'

ensuring that those resources are gener-
ated from within the company — from
its profits. No easy task, he admits.

"Coming from a financial back-
ground, you find all companies have a
great deal in common. The exceptional
thing here is the sheer speed with which
we are growing and the dynamism of
our research activities.

"It can be a problem to find the
resources to cover all that development.
It creates its own problems and puts
exceptional pressure on everyone who
works here but it also creates a much
more optimistic attitude among the
staff. We tend to pay better than the
normal market rates to get good people
and it is a marvellous team".

Matthews says the company philos-
ophy will always be to design products
which are inexpensive and produced in
large volume, thus making them widely-
available.

"I think the Sinclair computers are
marvellous little machines. We are just
seeing the beginning of a revolution in
the use of computers. The first stage

was to make them so inexpensive that
anyone could use them and Clive has
certainly done that.

"We have to be careful because the
life expectancy of our product is fairly
short. You can be fairly sure other firms
will catch-up rapidly. We have to make
the best use of that technical lead and
exploit il fully, to the best possible
advantage. We cannot afford to sit still.
In three years I do not suppose the ZX-
81 will be marketed. We are not making
pyjamas for Marks and Spencer after
all; that kind of thing you can probably
go on selling for about 200 years.

"We must have a stream of new and
innovative products all the time and we
must remain inventive".

Listening to those exacting standards
is tiring but they are the standards
which have taken Sinclair to the top SO
quickly and Matthews has absorbed
them with equal speed. Approximately
half the staff of Sinclair Research is
involved in research and development
and Matthews intends to concentrate
substantial resources for its continu-
ation, buying new premises and rational-
ising cvisting ones.

With Sinclair products tending to be
market firsts, Matthews admits there is
often a tendency to underestimate the
product, "When sales are restricted
they are restricted by the ability to
produce rather than lack of demand for
the product but one has to be cautious
to a certain extent,*' he says.

"You are making a commitment to
the subcontractor, so you have to be
careful not to over-estimate the demand.
Then the subcontractor has to buy com-
ponents and perhaps hire people. So
you hzve to be as realistic as you possi-
bly can.

''Producing new concepts means a
greater risk element and greater flexibil-
ity in financial control. You have to
keep re- assessing the situation in finan-
cial terms and try to predict what will
happen".

Because the Sinclair market is largely
domestic it is by nature more volatile
than selling to big industry. This is
another factor Matthews has to take
into consideration. With all that on his
mind, Matthews, who displays a Casio
calculator on his desk, has not yet had
much free time to experiment with the
Sinclair products.

His eldest 15-year-old son has com-
pensated for that. He has two Spec-
trums at home and, his father says,
spends most of his time sitting solidly in
front of them, lost to the world.

He has has two sisters, aged 12 and
13, and a five-year-old brother, but

none is yet showing the same enthusi-
asm.

Matthews likes to keep Fit in his spare
time and when I visited him was keenly
awaiting the Sinclair half- marathon due
in Cambridge on July 17, No newcomer
to running, be participated in last year's
Boston marathon. Nevertheless he was
taking the Cambridge event seriously .
So, no doubt, was one of his fellow
runners, Sir Clive Sinclair. Their
speed, it seems, is not confined to work,
nor their competitive spirit.

Matthews is reluctant to predict how
long he will stay with Sinclair but says:
"The chances are it will be a long time.
I am really enjoying it so far and with
the effects of recession hitting so many
companies, it is fine to work for one as
successful as this.

"We have built a very big turnover
and we have the financial resources to
expand into the future. That all gives
the company a great deal of strength".

As part of the Sinclair management

MUX MATTHEWS

'Sinclair compcilrr* an.- inur>i-lliput
link machine*

team, Matthews attends the monthly
meetings of the board, together with Sir
Clive, Nigel Searle the production di-
rector, and two research directors.

At the moment the board doubles as a
management committee which has en-
abled Matthews to look at every aspect
of the company within a short space of
time. He likes what he has seen and is
full of praise for everyone, from the
genius of Sir Clive through the dedica-
tion of the rest of the staff down to I he
excellent quality of the company can-
teen.

In short, he appears to have been
converted and he speaks as if he has
been with the company for years. St
George's, Weybridge should be proud.

SINCLAIR USER A»»ua! 1934

65

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old or otnerwise circulated withoui cne written permission of Ricrwd Shepherd Software Litf

We meet the people who deal with your queries and complaints.
A behind-the-scenes look at the Sinclair mailing house

The go-betweens

SINCLAIR RESEARCH com-
puters are now in a class of ihtir
own in the home computer market,
which the company has done
most to create. Despite its policy of
selling many of its products by mail
order, however, few of its customers have
had direct contact with the company.

The reason is one of its other well-
known policies — Sub-contracting, As
much as possible of the business of
making and selling Sinclair products is
delegated to outside companies, allowing
Sinclair Research to have a very small
stafT, slightly more than 50 at the
moment.

Most people who manage to obtain
their machines and software without too
much trouble find that the nearest they
get to Sinclair Research is a company
which worts from small offices and a
warehouse on a featureless industrial
estate in the Surrey town of Camberley.
The offices are those of GSI U.K., the
address and telephone number of which
appear in Sinclair advertisements and to
which the mail order coupons are sent. It
is GSI which has the task of being the first
line of complaint and query, answering
the growing number of Sinclair users
throughout the country. It is also the GSI
switchboard which plays music to soothe
the patient person waiting for a query to
be answered.

GSI U.K. is the British subsidiary of a
French company which has built a
reputation as a supplier of marketing
services to the motor trade. It maintains a
mailing list for a large number of motor
dealers which can be used when a
particular group of people need to be
contacted. GSI also looks after the
despatch of the information.

NIGEL BROWN

In charge of the Sinclair account

With its associates, GSI claims to be
the biggest computer bureau for the
motor trade in Europe. Its ultimate
parent is CIT-Alcatel, a division of CIT,
the power generating company which is
the private equivalent of Britain 1 *
Central Electricity Generating Board.

The expertise for large mailings with a
certain amount of mail order distribution
led to the company being considered
when Sinclair was looking for a
distributor.

"'We had a good deal of experience with
keeping names and addresses on file and
mailing, so it was natural to start doing
something like the Sinclair work," says
Nigel Brown, product manager at GSI,
who is in charge of the Sinclair account,

"We started working with Sinclair in
October, 1980 when the ZX-80 was still
being produced. Before that Sinclair had
looked after ?he distribution and we
needed only four people at that stage."

At that time the company was known as
Jjsenfe, changing to GSI when it was
taken over in April, 1981.

"With The ^ajnch of the ZX-81 in
March, 1981 the work became much
bigger, which was when I became the
account manager, "Brown adds.

Njw there are 58 people working
exclusively on the Sinclair contract,
which has grown to become a substantial

63

SINC1-AFR USER Annua! 1984

part of the British company's turnover.

Every one of the Sinclair products, the
range of which now includes two
computers — with different versions for
the different television and power
systems throughout the world — a
primer, printer paper and a growing
amount of software for all uses, passes
through Camber ley on its way to the
corners of the world.

Each day two large, articulated
container lorries make the long journey
from Dundee to Surrey with the latest
batch of SpectrumSj ZX-81s and
printers. Another slightly smaller lorry
takes more products from the other
Sinclair suppliers.

They all go into the large, highly-
secure GSI warehouse but rarely stay for
long. The items to be sent to distributors
in export markets are sent to another
warehouse, leaving GSI to deal with the
distribution in Britain and those
countries which have no agents.

Many items go almost immediately to
the growing number of retailers now
stocking the Spectrum and the ZX-81,
while the rest go in batches of 50 to the
mail order customers.

When the mail order system is running
smoothly there is a clear number of stages
in the processing of each order. Every
morning the post is sorted into the
queries and the orders, which are then
further divided, depending on the goods
required and the method of payment.

Cheques and cash are paid into a
special holding account, where the
money stays until the order has been
satisfied; then it is transferred to the
Sinclair sales account. Credit cards are
not charged until the order has been
fulfilled.

The orders are then entered on the
computer and all the data stored on tape.
When the goods are available to be sent,
address labels are printed and another
Spectrum or box of cassettes is ready for
the post.

At the moment it is possible for GSI to
say which stage a particular order has
reached but not where it is within that
stage. That resulted in many complaints
during the Spectrum delay difficulties
last year. Although an anxious customer
could be told that their order had been
received but was not about to be
despatched, they could not find the place
of their order in the queue. A new system
is being installed which will allow the
state of orders lobe seen at a glance.

Brown adds that at the height of the
problems it was difficult to be more
specific, so that customers were not
misled.

"We could give only general replies as
the situation was always changing, so we
thought it better not to give a specific
answer which might then have to be
altered," he says.

"Sinclair made a policy that everyone
should be kept as informed about the
position as possible and I think we were
able to achieve that."

Most of the queries and complaints
were by telephone, a customer service
which has grown rapidly along with the
rest of the Sinclair business. In October,
1980 there were only two lines. They
have grown in stagey first to four, then
eight, then IS, and last summer another
10 were added.

"In the early days on our two lines we
were receiving about 100 calls a day.
When the ZX-81 was launched that
exploded to 1,000 a day. Now I think we
probably have a capacity of about 2,000 a
day," Brown says.

The calls deal with a vast number of
subjects. Apart from complaints about
The warchuusr filled with Sinclair products

non-delivery or faulty machines, many
users need advice on particular aspects of
u sing t he machi n es , Som e t h i n gs, sue h as
saving and loading difficulties, arc the
subjects of regular queries and there are
almost 40 leaflets giving advice which
can be sent.

For t he more com p I icated que r i es t here
are three more technically-minded
people available who attempt to find an
answer.

Whatever the difficulty most of the
callers are still polite. Even when the
delays were at their worst last year, no-
one became abusive when making
complaints.

The GSI position as the public face of
Sinclair Research will be reduced as the
retail sales of Sinclair products increases.
It is likely to remain the first place people
will contact with their problems and
complaints and will remain an important
part of a string of companies involved in
the production and selling of Britain's
most popular computers-
ready for despatch

SINCLAIR V\ir Arrnuat

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72

SINCLAIR ISJ-R Annuai 1984

Futurology

A speech by Sir Clive Sinclair to the British

Mensa Society on the expectation of a new

Golden Era being caused by the growth of

computer use began a series on what people

believe will be the result of the increase in

computer ownership.

5IN( ] UK VSl-K Annual Sfrf

71

fii

Computers bring
new Golden Age

Sir Clive Sinclair sees a bright future

A S WELL as being head of Sinclair

I-\ Research, Sir Clive Sinclair is

X A chairman of British Mensa, an

exclusive club whose members have IQs

which reach the genius level.

In a speech at the Mensa Golden
Ages symposium at Cambridge, Sir
Clive outlined his ideas for the furure,
not of his range of personal computers
but of the Western civilised world. He
said: "I intend arguing that the most
Golden Age of man's history may well
lie before us, if we can only move in the
right direction."

The new age would need to be trig-
gered by an event which will startle
society. The trigger, he explained,
would be something similar to the in-
vention of writing or moving type. He
said: "Both of those developments re-
duced the cost of data transmission by a
factor of 100"

He saw leisure) or periods of time not
occupied by formal work, as an oppor-

tunity to broaden the mind. If the trig-
ger occurs at the proper time and the
Golden Age arrives "the body of men
arises which can turn its attention to
matters other than necessities. Thus
wealthy patrons produce the great
flowerings of arts which are a feature oT
the Golden Ages.

"Equally, the Golden Ages are often
marked by one great individual, a type
of philosopher-prince, e.g., Pericles,
Augustus, Lorenzo de Medici, Eliiia-
beth I and Louis XIV."

In business operations, Sir Clive
seems to regard the personal approach
best — one man at the head of a com-
pany. He has stressed that approach
many times through Sinclair Research,
so that now he is as famous as his
machines, whereas other manufacturers
remain masked by their company exter-
iors.

During his speech he referred his
ideas to the present day. He saw the

Golden Age as being very close. Some
of the features which marked the Gold*
en Ages of the past could be identified
within our time. That could place us on
the threshold of a new Golden Age. To
demonstrate it, Sir Clive returned to the
idea of a trigger.

"Is there a trigger? It SO happens that
another hundred-fold reduction in the
cost of data publication and transmis-
sion is about to occur. A single I2in.
diameter optical disc, being developed
for use with TV tan, remarkably
enough, contain the information of
10,000 books and lhat disc will cost not
much more than a few books — almost,
in fact, a thousand-fold reduction in
costs."

The reduction in costs and the inno-
vations in mass marketing are compared
to what Sir Clive calls "the potential of
the individual". Until now, society has
accepted that people will work together
in large groups. People work in large
companies, they commute into towns
and cities every working day. That
massing of the working population is
the motive force behind the present
state of the economy.

Sir Clive said: "We have for some
time been passing through a great in-
dustrial age in which the economic basis
of society has demanded the bringing
together or people in great numbers,
many thousands per factory, many mil-
lions per city. I believe that our move
away from this type of organisation will
restore the potential of the individual."

Individual human potential is some-
thing he seems largely to favour. While
Sinclair Research is a company, like
many others, where everyone pulls
together, it is still mostly a one-man
operation. Sir Clive is the man who
defines what he wants and lays-out the
timetable for its development.

That style of operation has so far
proved successful, first with the ZX-80
and ZX-81 and then with the Spectrum
The hundreds of firms which give sup-
port 10 Sinclair microcomputers would
also seem ro prove his point to be
correct .

He sees the new Golden Age as being
a time of the mind^ with less stress put
on the body and building culture rather
than labouring. He feels that another
Golden Age requirement is an abundant
supply of patrons, people who can ap-
preciate, as well as create, art.

"We have a well-educated popu-
lation, a society which reveres the arts,
and have become a world centre for
music and for the written word."

The reason for the swing towards

SINCLAIR USER Awaa fJSi

cultural pursuits is marked with the
stigma of a current curse on society.

Sir Clive said; "We have potential
artists, partly for the sad reason that we
have three million unemployed; this is
not a passing phase of recession hut a
trend which will last until the end of the
century j during which I expect the
manufacturing industry to shed a fur-
ther seven million jobs and for the
proportion employed in manufacturing
to decline from some 42 percent of the
population to less than 10 percent. This
will occur as automated systems are
now radically cheaper than manual
costs."

The resulting factors of unemploy-
ment due to technological innovation
and automation will leave the popu-
lation with a great deal of spare time if
present trends continue. If the number
of unemployed rises to more than 90
percent it may be necessary to re-define
the term altogether,

"Many, if not all, of today's young
people will always work for small or-
ganisations and indeed must found
them. We must encourage people to
follow this route if we are to create
future employment— whether in high
technology, in a revival of a class, or in
service industries."

Sir Clive foresees a new "creative
endeavour". People are experiencing
new technology, seeing what it can do
for them. It can relieve them of manual
tasks so that they can use their minds
more fully.

Young people were just beginning to
learn about new technology. According
to Sir Clive, the learning process would
be only the beginning.

Learning about new technology
through machines such as the ZX-S1
and the Spectrum which, because of low
prices, were within the reach of nearly
everybody., was the beginning of a
process which may lead to what he
believes is a new Golden Age.

"Because we no longer need to
devote the bulk of our time to the
production of objects, I can see the
plateau of a Golden Age before us.
Certainly we may need inspiration and
leadership, great building, a bridge over
rather than a tunnel under the Channel.
"Early in the next century we will
have made intelligent machines ending
for all time the pattern of drudgery- It
may be th^t Western civilisation, seeded
in seventh-century Ireland, is only just
about to flower."

To some, his ideas may stem like
science fiction but some cynics said that
a machine like the Spectrum was not
possible only a short time previously.

Less work, more
computer play

Future leisure activities surveyed

MORE THAN 2,000 years ago,
Aristotle made the comment
. that we work to have leisure.
For him, leisure was a reality, since all
the toiling and much of the producing
was done by human slaves. For most
other people then, and since, work has
been the essential part of human life as
people have struggled just to survive.
Leisure has been, at the best, a residual
and generally meagre amount of time.

Today, because of the introduction of
computers and microprocessors, we are
developing a new type of slave, in the
form of electronic robots of all kinds.
That represents a major change in our
lives, which will give new meanings and
new dimensions to work and leisure.

Perhaps, most of all, new technology
means a growth in the amount of leisure
time. That is not an unmixed blessing.
Although people will need to work less,
they will also have to learn how to
develop their lives in the way Aristotle
meant when he talked about leisure.

In some measure, we have already
entered an age of leisure, with a mile-
stone at the beginning of the 1970s
when the amount of time the average
full-time worker spent at work during a
year fell below the amount of time
available for leisure.

Since then, a typical worker's leisure
time has increased by some seven per-
cent to more than 2,500 hours a year,
while the number of working hours has
fallen to 1,950, including travel to and
from work.

Less positively, we now have the
large amount of enforced and mal-
distributed free time represented by
more than three million unemployed.

With the expansion of free time and
the need to find ways of occupying it in
a satisfying manner, the development of
the microcomputer, with its time- inten-
sive quality in use, seems to be particu-
larly fortuitous. Certainly home
computers will become increasingly im-
portant in people's lives but we need to
be realistic about just how fast private
ownership of computers will develop
and also about exactly how the
machines will be used.

Without becoming involved too

deeply in the psychology of leisure, it
helps when thinking of the possible
roles microcomputers might play in our
leisure lives to consider for what we use
our leisure. It is possible to identify
three functions of leisure which form
something of a hierarchy— rest and re-
cuperation from work, entertainment
and the relief of boredom and, finally,
personal and social development.

In the era of leisure we are entering
the function of leisure as rest and recu-
peration declines in importance as the
amount of work lessens and the effort
involved decreases. That puts the em-
phasis in leisure time use on the two
other functions of entertainment and
self-development, both areas where we
expect to see the microcomputer play an
increasingly large part.

An obvious role microcomputers play
in the area of entertainment is of being
virtually an infinite compendium of
games. They can provide an unending
source of pastimes for those who wish to
occupy their leisure in this way.

It could be argued that people could
use a chess set or a pack of cards instead
of a microcomputer for those simpler
activities. The answer lies probably in
the basic attraction of using new tech-
nology, as well as in the perpetual self-
challenging quality of computer games
and the wide variety of pastimes avail-
able from the one machine.

Once attracted to the computer, the
games player is likely to look progres-
sively for more complex games to play
and may eventually take the step to-
wards developing improved or original
programs. At that stage, the computer
moves from being a source of entertain-
ment to potentially a very time-consum-
ing hobby, offering great opportunities
for individual learning and develop-
ment.

Many people have turned to micro-
computers without any particular em
phasis on games playing. Either way,
and whether interest lies primarily in
the hardware or software, all computer
hobbyists have found a leisure occupa-
tion of absorbing interest. In the future,
when there may be considerably more
free time but possibly not so much extra

SINCLAIR USER Annual 1BS4

75

—

money to spend on leisure, the time-
absorbing nature of computing is a valu-
able characteristic.

In addition, as members of computer
groups know, there can be a strong
social element in the hobby., producing
new friendships as well as a useful
exchange oT experience and ideas.

There are other aspects of what we
have termed self- development in which
we believe the microcomputer poten-
tially has an important leisure role to
play. By self-developments we mean the
whole process of learning and enlarging
one*s menial and physical capabilities
with the aim of leading a fuller and
richer life.

Naturally the microcomputer cannot
take the place of weight lifting, jogging
or other sports in improving physical
capabilities but, as a provider of aid to
educational and cultural development,
it could have a vital part to play. Pre-
viously it was often people of leisure
who went to university to enjoy rhe
benefit of learning, often for its own
sake; in the futures the micro will help
to take learning to the homes of all who
want it.

How quickly will all this happen?
How soon can we expect to see a micro
in every home, as some commentators
envisage? How many people will, in
practice, be encouraged to use this new
gadget to educate themselves and their
families?

Our forecasts appear to be somewhat
more conservative than those of many
others. We expect that, by the end of
the decade, something like one-fifth of
ali households, some four million
homes, will have a micro bought for
personal use; others, as now, will have

machines used both for the business and
family.

Behind that view lies the assumption
that microcomputer prices will fall to
around one-third of what they are at
present. An even sharper fall in price
obviously would boost demand. We do
not think a very high proportion of the
33 percent of households where the
head of the household is over 60 years
of age will be buying a microcom-
puter, even if it costs only £10.

Despite the growing amount of free
time, the majority of people are likely to
be fairly slow to recognise what the
microcomputer can offer them. The
attraction of games-playing is obvious
but for many people the idea of leisure
as a period of education is a novel one
and, during the 1980s, most of the
demand for educational use is likely to
be stimulated by children's needs.

It will probably not be until the
1990s, when the first generation of chil-
dren to whom computers are a part of
everyday life become adults, that a real
widespread educational use of home
computers will develop.

Since many people, not least the un-
employed, will be having a leisure prob-
lem well before then, we hope that
those already keen on computing will
do all they can to try to make our
forecasts seem too pessimistic.

Aristotle probably would have en-
joyed the challenge of microcomputing
but even he might have needed some
encouragement to take the first steps in
this new leisure direction.
• Bill Marriti and Sandra Mason of
Leisure Consultants, Sudbury, Suffolk
have published a report on leisure in the
1990s.

Micro
junkies

Chris Reynolds

M4NY YOUNGSTERS have
home computers because
they, or their parents, feel
that owning such a computer will help
them in their careers. As a universnv
lecturer responsible for training future
computer professionals, I have my
doubts. Let me explain.

In the last 3D years the uses of com-
puters as part of practical working in-
formation systems have mushroomed-
For most of that time there has been a
desperate shortage of suitably-exper-
ienced staff. Salaries rocketed as com-
panies bid to obtain employees with the
greatest length of experience, apparent-
ly regardless oT quality. The whole was
surrounded with the prestige of being at
the forefront of modern technology, at
least in the eyes of one's neighbours.

Much of the gloss has now been shed.
There is, of course, still a shortage or
good computer professionals but the
incompetent now find it almost imposs-
ible to climb on the bandwagon, and
salaries are no longer so wildly our of
line with other occupations. One no
longer hears people boasting that they
know someone who knows someone
who works with computers. In fact, it
seems likely that in five years having a
computer in the house will be socially as
significant as is owning a digital watch
today. When acne-embarrassed school-
boys with home computers are ten-a-
penny the simple ability to program will
have no value in the job market.

Those changes will have a major
effect on the structure of the computer
profession. The need for highly-skilkd
people to work on research and develop-
ment projects in the computer industry
will continue. The majority of existing
professionals work for companies which
use computers as tools to help the com-
pany business and it is in that area that
the biggest changes will rake place. The
pressure will be for more flexible and
easier-louse systems with the minimum
of fuss.

A prime requirement will be for staff
able to communicate with other people,
verbally and in writing, with the mini-
mum of jargon. Knowledge of manage-
ment, economics and psychology, and

76

SINCLAIR USER Annual IM-t

the design of systems are next on the
list, A good understanding of what a
computer can reasonably be expected to
do is of far greater importance than the
ability to PEEK and POKE on a par-
ticular make of microcomputer.

Universities already have moved in
that direction and introduced courses
which anticipate that future need, For
instance, Brunei University has a Sys-
tems and Information Management
course which has been running for five
years and which attracted 28 good stu-
dents this year, compared to 22 on its
more conventional course. Because it is
felt that breadth of experience is im-
portant, students who do not have A
levels in computer science and math-
ematics are preferred to those who have
already specialised narrowly with
double mathematics and computer sci-
ence.

Many of the leading 21st century
computer professionals are now at
school and in the light of the foregoing
comments., it is useful to speculate what
they are doing now. We can be certain
that they will be well-acquainted with
modern electronics technology. Digital
watches and pocket calculators will be
taken for granted. Their parents will
have television sets with teletext and a
variety of electronic games. As soon as
they are old enough they will use auto-
banks and credit cards to buy things
such as electronic organs. Even if they
never saw a general-purpose computer
they would take for granted keys to be
pressed) video displays, and automatic
information processing.

While at school they will almost cer-
tainly have been given a computer ap-
preciation course and may have had
computer-aided instruction. Most will
have taken O and A level computer
science. That will not be because this is
necessary for their careers but because

'The pressure will be

on for more flexible

and easier-to-use

systems'

the education system encourages early
specialisation.

Sociallyj most of them will be good
mixers. They are therefore likely to be
found in the Boy Scouts, the school
band or the local cricket team.

One thing not mentioned is owner-
ship of a home computer. The reason is
that the evidence at Brunei suggests

that in many cases a private micro can
have an adverse effect on student
studies and sometimes on employment
prospects.

There are a number of reasons. The
first is that to understand and use a
language well, you have to be able to
think in that language, be it French,
Arabic, Pascal or Cobol. Students who
have written a large number of pro-
grams in a single language, often on a
single machine, have difficulty in trans-
ferring to other languages.

Gerald Weinberg, in his book The
Psychology of Computer Programming,
showed how easy it was to guess a
student's former language by the stylis-
tic errors he makes in learning a new
language. Ten years later the problem is
much the same. Most novice students
learn rapidly the essentials of modern

puter is bought by enthusiastic parents
to encourage him in what is certain to
be a wonderful career in this marvellous
technology. He is delighted to be al-
lowed to spend many hours every even-
ing enjoying himself in the privacy of
his room. Socially, he finds he can boast
about his wdnderful programs which
look most impressive, with flashing
screens and perhaps even sound effects.

Because of all this praise and the
absence of anyone who can assess the
quality of his work properly, he soon
becomes convinced that he is a com-
puter genius and spends even more time
at the keyboard, He has become a code
junkie who craves for his two-hours-a-
day session at the keyboard.

In fact, the idea of code junkies is not
new. In the last decade wc have had
several who have become addicted to

'The big danger seems to be the bright but
socially-gauche adolescent. He finds the
school computer more friendly than his
school-mates and develops an interest rapidly'

programming concepts, such as block,
structuring and recursion

Students who have extensive experi-
ence in old-fashioned languages which
lack those features often insist on using
more powerful high-level languages as if
the newer features did not exist. That is
apparently because they find it easier to
write longer, inelegant programs than
to learn something new.

The second problem is that writing
programs and playing games on a home
computer is most entertaining. The
ability to use a home computer is, how-
ever, of little relevance to any but the
most junior jobs in the computer field.
Most adults would discourage a child
from wanting to become a television
news reader simply because he had built
a crystal radio at the age of eleven.
Unfortunately computers are so new,
and so mysterious to many adults, that
most teachers and parents are not suffi-
ciently knowledgeable to recognise a
fun hobby as just that and, as a result,
they encourage children to attempt to
follow a career path for which they may
be almost totally unsuited.

The big danger seems to be the
bright but socially-gauche adolescent.
He finds the school computer more
friendly than his school-mates and de-
velops an interest rapidly. A home com-

the university computer, From experi-
ence we know that almost all such
students fail the course. They prove to
be almost unemployable because of
their inability to get on well with
people, and because of a marked reluc-
tance to work with, rather than play
with, computers.

In 1981, for the first time, we had the
problem of new undergraduates who
were already code junkies before they
arrived. This year the number of stu-
dents who have home computers on
arrival has more than doubled and it is
suspected that many of them will prove
to be junkies.

Ii has heen said that home computers
and computer games will help to keep
the future unemployed occupied in an
enjoyable manner. That may well be
true in the long term, when society has
become adjusted to the new technology.
In the short term there is a danger that
the majority of the unemployed who
play such games will be code junkies
who caught the bug during a vulnerable
period of adolescence.
• Dr Chris Reynolds is reader in com-
puter science at Brunei University, fie
organises (he computer science teaching for
fir st -year mathematics computer science
students. He also researches improved sys-
tems for the man-computer interface,

SINCLAIR USER Annual 1984

77

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79

Hooked on
arrogance

J R Bird supports micro training

COMPUTING is much more
than programming. It is con-
cerned with the flexible use
and application of ideas. The ideas are
structured logically by means of a lan-
guage.

Thar is one of the reasons why many
of the conclusions of Dr Chris Reynolds
are incorrect. Although much of what
he says is valid, the tone was prejudiced
and negative-
All the problems of vocational com-
puter training were blamed on owners
of the home computer. The only slight
comment in favour of the powerful little
machines appeared in the last paragraph
but even then they were dismissed as
little more than games machines.

To condemn home microcomputer
owners as potential code junkies-
people with an addictive, perverse inter-
est in computers— probably as failures
in academic life and as unemployable is
a form of professional arrogance. Most
people who have an interest in comput-
ing also have other interests.

It is the same arrogance which leads
many people to claim exclusive rights to
comment on particular branches of
knowledge, especially how those
branches will develop in the future.

There are likely to be many problems
associated with the future in areas such
as jobs or careers, leisure and education.
None of those can be answered by any
one group , be they teachers, employers,
lecturers or workers, claiming they have
the exclusive right to comment and
decision-making.

Neither should Reynolds be advocat-
ing novice students in computing. That
kind of logic is rather like a professor
French insisting on novice speakers—
thaw who do not spt.::ik yet— if he is to
produce good speakers of French,

A teacher of a foreign language must
take account not only the students' own
language but also their development
within that language.

If a student has had experience of a
computer language it is reasonable to
expect lecturers to take it into account.
If specific languages cause problems,
the lecturer must identify the problem
and work out ways of overcoming them.

A lecturer should not advocate novice
students; it is no solution.

There is a clear and unfortunate rift
between academics and non-academics,
professionals and amateurs. Academics
tend to be more concerned with protect-
ing their access to knowledge rather
than sharing it. Professionals seem robe
more concerned with keeping their
right to knowledge rather than sharing
it with amateurs.

Computing at a high level is for a
small number of highly-qualified stu-
dents and to suggest that the needs of
those few are best served by denying the
vast majority of home micro owners use
of their leisure time activities is wrong.
Academics appear to see things in one
of two ways. Either they are shut in
ivory towers researching and learning

'To condemn micro
owners as failures is
a form of arrogance'

for pure knowledge, or are selling their
ability to industry.

While 1 should not subscribe wholly
to that view, 1 wish the apparent rift
which contributes to it did not exist.

With the introduction of new tech-
nology, people will find vast changes in
their life-style; work may never be the
same again. The concept of five to 16
education being sufficient may disap-
pear: re-training several times may be-
come the norm.

Most people with home microcom-
puters would not suggest that their
work with the computer would change
the world but they would not suggest
that those with computer PQX were
inferior to them or that all mainframe
work was necessarily superior.

The assumption common to many
vocation-minded computer studies/com-
puter science lecturers, that their work
was import ant j simply because they
train professional workers, is to misread
the future. Before long., the day of the
large "brain" will be over and the day
of the small, powerful computer will
begin.

It is also clear that plain language or
even interactive voice computers are on
the way. When the man in the street can
talk to a computer and ask it questions,
the mystery of the languages probably
will disappear. Before that day arrives,
however, we have the problem of many
computer languages, but it is surely not
beyond the understanding oT profes-
sionals in the computer field to struc-
ture courses to take that fact into
account.

I notice that the Open University is
to use a further form of Basic in its
course Computing and Computers. I
am not condemning ihe intellectual lev-
el of the OU course but rather regret-
ting the introduction of yet another
dialect.

Even with the limitation of the new
OU SEA SIC, the Open University is
showing the way to other universities
and polytechnics. The course has been
designed to introduce beginners to skills
and techniques of computing. Most mi-
cro owners would concede that their
programs and computing would be im-
proved for a better knowledge of struc-
ture and logic, not to mention better
techniques.

So, in effect, what we have is a
university or polytechnic department
with the skills and resources to teach
both the structure and techniques to
improve the standard of home micro
owners. Alongside that pool of skill we
have a large number, perhaps some half-
million at the moment, who would no
doubt welcome some of that skill being
taughr to them.

What better way of bridging the aca-
demic, professional and non-academic
amateur rift than bringing the two
together?

That would create a new area of non-
vocational studies for the institutes of
higher education. As a spin-off, it would
also retain in those institutions some of
the reaching jobs which are disappear-
ing under the present retrenchment in
the higher education sector.

Clearly there would be advantages lor
the students of such courses. They
would learn better techniques, they
would learn better ways of using com-
puters, they would karn other com-
puter languages, not to compete with
the professionals but to use in their
private studies.

The interaction between micro
owners and the professionals, both at
the formal teaching and informal social
levels, could only benefit both. Experi-
ence from both sides could stimulate
more courses and lead to a leisure time
education industrv.

ao

.!R I SF.K Annual! 984

Books

Publications of varying quality and quantity

have gone on sale during the year. John

Gilbert looks at the growing bookshelf and

selects some typical examples of recent

developments.

SrHCLAIR USER Amtml 1984

HI

h^L
*. *■*«

• sasss&-

John Gilbert assesses publishing

Young authors
get opportunity

THE COMPUTER publishing
market has developed so quickly
this year thai publishers have
been desperate to lay their hands on
anyone who knows something interest-
ing about Sinclair computers, program-
ruing techniques, or who has some
programs they want to sell,

Some publishers have even asked
teenagers to write books because insuffi-
cient adult writers have been able to get
to grips with the subject. That kind of
move sets a precedent in the publishing
industry. No other sector has ever
sought young writers with such vigour.
If you can write and you have an above-
average knowledge of computers there
is a good chance that a publisher will
contract you for at least one book. The
problem is, and has always been, that
young writers know little about the
publishing industry and, through no
conscious fault of the signing company
or the young author, writers do not
obtain everything they should. Fortu-
nately that does not happen often but it
is a side-effect of the market growth and
the urgency with which publishers seek

titles. The youngest writer of the year
must be Patrick Hossert, author of the
Penguin You Can Do The Cube, In
August j Penguin released one of its first
micro-computer books by the 14-year-
old. Unfortunately Micro Games was
little more than a book of listings, a
stage though which many companies
such as Shiva Publishing, Interface and
Melbourne House passed earlier in the
year.

Penguin seems to have relied on Bos-
sert's fame with the Rubik Cube and
that the puzzle and computers share the
same intellectual image in the public
mind. Just because Bossert can do the
cube, however, does not make him an
automatic genius at computer program-
ming.

The concepts for most of the pro-
grams in his book existed earlier in the
year when all you could buy in terms of
the Spectrum were books of Listings,
There is little that is new in the title — a
pity, since it is from Penguin, a publish-
er renowned for its quality of output.

Books of listings were popular at the
beginning of the year when the ZX-81

had more of the limelight than the
Spectrum. Authors such as Tim Hart-
nell were having at least one book pub-
lished a month. Most of those books
were for the ZX-81, as most publishers
had not yet advanced to the Spectrum,
although it was launched in April,
1982,

Before the beginning of 1983 the
only publishers to try for something
extra from the ZX-81 were Interface,
Melbourne House and Shiva, All were
still small but it is a mark of their
innovation which shows their success
and expansion to date. Now all three
have a large share of the publishing
market where Sinclair machines are
concerned.

By May all three companies had done
something different for the Spectrum
market. Machine code programming for
the Spectrum was a subject which
would sell books and the big three
publishers knew it*

Shiva produced Spectrum Machine
Code, by Ian Stewart and Robin Jones.
It was launched as part or the Friendly
Micro series and, although it did not
cover the area in as much depth as some
of the American books about the Z-80
processor, it provided an excellent
grounding in machine and assembly
language. It also added a humorous
element missing from many other books
with 'bug' cartoons spread throughout
the pages.

The other publisher renowned for its
stock of titles on machine code is Mel-
bourne House, It has two machine code
titles which cover the ZX-8 1 and Spec-
trum. Both are similar in approach and
it seems as if the Spectrum version was
edited from that of the ZX-81, with
extra examples showing colour and
sound added.

The other range of machine code
books from Melbourne House is by Dr
Ian Logan and, in the case of The
Complete ROM Disassembly, written
with Dr Frank Q'Hara. The books are
excellent value and contain a good deal
of necessary information for the ma-
chine code programmer.

Because of his knowledge of the Spec-
trum ROMj Logan was asked by Sin-
clair Research to write the routines for
the Microdrive ROM. As a result, and
with the blessing of Sinclair Research,
he wrote the Spectrum Microdrive Book.
It includes much information about the
drives, Interface One and the possibility
of adding or patching-in extra com-
mands to the Basic.

The emergence of the book resulted
in a rash of similar texts from publishers
trying to keep in the race for the most

82

SINCLAIR I'SkR Annual 1984

up-to-date information. In most cases
the follow-up texts represented a re-
arrangement of the original but, unfor-
tunately, that is not so with the new
Microdrive texts from Interface and
Sunshine Books.

When first exhibited at the Personal
Computer World Show in September,
the Interface book was little more than a
slim cardboard-bound photo-copy. It
was planned to use it as the basis for a
'proper' publication. The Sunshine ef-
fort, however, was better-presented.

The author of the Sunshine Master
Your 2X Microdrive is Andrew Pennel,
a friend of Logan. His book contained
information which Logan's could not.
One reason was that he was not limited
by what he could say. Although Logan
speaks with an authority which is diffi-
cult to match, Pennel's book is slightly
better as it contains information which
Sinclair Research did not want used in
Logan's book.

Even with the restrictions, however,
the Logan book is good value so far as
money and information are concerned.

The release of the Microdrive texts
has introduced a new area to the com-
puter publishing market. We have had
books on machines, books of listings,
and books showing software techniques
but there had, until then, been no books
on one specific peripheral for a ma-
chine.

The Microdrive seems to have
opened an area which could soon in-
clude how to get the best from your
sound generator or using a disc drive
with a Spectrum, Book titles such as
that may seem absurd now but with the
way books are becoming so machine-
dependent, and with the search for new
areas to write about, such titles may
become available.

The information in the Melbourne

House book on the Microdrive contains
a good deal of machine code. The pub-
lisher is Still determined to introduce
machine language anywhere it can and
the release of another machine code
book for the Spectrum was inevitable
before too long. The new book is Super-
charge Your Spectrum and many pages
are occupied by machine code listings.
They include routines to search for
strings in programs, re-number lines,
and delete blocks of lines. It has proved

The new book improved that situ-
ation, however i and showed the reader
how to write graphics adventures. Little
is said about decoding player responses
or generating textual adventures but the
book still marks a new area for publish-
ers to exploit.

While the areas which belong to the
games and utility sector have developed
by leaps and bounds, the business and
education markets are still nothing
more than a mess. Little has been done

'While the areas which belong to the games

and utility sector have developed by leaps and

bounds, the business and education markets

are still nothing more than a mess'

extremely useful to Spectrum owners
who know nothing about machine code
but who want toolkit routines without
having to buy several cassette-based
programs.

It is useful in another respect. It is
possible for someone just learning about
Z-80 machine code to read the program
listings and get an insight into how
programs are structured and the way in
which some statements can work with
others. It also provides an incentive to
use some of the routines in your own
machine code programs.

Not all publishers are interested in
machine code and th* market has plenty
of support from companies with other
ideas. Yet another new type of book was
launched for the Spectrum by Sun-
shine, Until the release of Spectrum
Adventures, by Roy Carnell and Tony
Bridge, computer owners interested in
adventure games-playing or writing had
to rely solely on magazines.

******

te*l

in book form to aid this ailing though
very important part of the industry.
There have been a few general books on
business applications, such as Databases
for Fun and Profit from Granada, but
little business-orientated work has been
done.

The same is true of the education
market, although some publishers, such
as Granada and Longmans, are starting
to see the potential. The object seems to
be to produce as many programmer-
orientated books as possible. Unfortu-
nately that leaves the market for the
computer user who does not want to be
bogged down by technology as undeve-
loped as it was early in the year.

Several new areas in the publishing
industry include machine code pro-
gramming and programming tech-
niques. They are over-developed and
that is proving expensive to the Olhcr
users who want to use Spectrums at
home or at school for accounts or home-
work.

In the end that can only do the
market and, indirectly, computer manu-
facturers, a good deal of harm. The
areas in which computers can be used,
such as education and business, will be
under-developed. Many children will
know how to program but very few will
have ideas on how to use those program-
ming talents.

Interface, 44-46 Earls Court Road, London

WB 6EJ.

Melbourne House, 131 Trafalgar Hoad,

Greenwich, London SE10.

Puffin Books, Penguin Books Ltd. Har-

m-Qfidsworth, Middlssex.

Shiva Publishing, 4 Church Lane, Nantwith,

Cheshire CW5 5RQ.

Sunshine, 12-13 Little Newport Street,

London WC2R 3LD.

Granada, 8 Grafton Street, London W1X

3LA.

SINCLAIR USF.R Annual 1984

83

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84

SINCLAIR USER Annua! MM

One of the most popular sections of Sinclair

User is our program listings. We have

reprinted some of the best, with two listings

which have not been published previously.

SINCLAIR I ISER Annual 1984

£5

To help with entering graphics characters we have adopted a
system of writing the characters for the ZX-81. We indicate
inverse characters by the letter i and graphics by g, so that an
inverse letter W is shown as iW and the graphics character on key
6 ii denoted by g6. Spaces uie shown by sp and inverse spaces are
isp. If some occur together, for instance a row of sia spaces , they
are shown by *6sp and where there is a combination of characters
each one is divided by a colon, thus sp:isp:6*g6 means a space
followed by an inverse space and then six characters on the 6 key,
Where whole wurds are written in inverse letters they appear in
the listings as lower-case letters.

In the Spectrum listings, letters to be entered in graphics mode
arc underlined, white other graphics instructions are underlined
and take the form shown above, with ihe addition that inverse
graphics characters are represented by the letters "ig".

KEN RYLETT of Burnage,
Manchester wrote Solitaire
for the 16K Spectrum to allow
people to play the traditional game,
Move one spot over the next to an
empty space. The peg which has been
jumped will then disappear. The aim is
to finish with only one spot remaining.
Moves should be entered as number,
then letter,

Letters to be entered in graphics
mode are underlined.

GO SUB 9000

BORDER 5; PRPER 5« INK

CLS

FOR n«l TO 64

LET PCtO-l

PRINT BRIGHT I) INK 2;

RT VCn>,HCrO; "a"
NEXT n

FDR n-20 TO 148 STEP 16
PLOT 60, TV DRAW 126,8
NEXT n

FOR r ( ^69 TO 188 STEP 16

1915
1020

1030
1040
1030

1060
1070
1080
1090
1100
1110
1120

1130
1140
1150
1160

H"
1170

1180 PRINT AT 4,6U;RT 6,6;2jRT
8,6;3;RT 10,6j4jRT 12,6j5jRT 14,
6iSjRT 16,6;7;RT 1B,6jB
1190
1200 PRINT RT V<28),H<2S>; " " j RT

V<29>,HC29>.i tt "jRT V<36),H(36)j
" H ;flT V<37>jHC37Jj" "

PLOT ty,£0
NEXT n

DRAW 0, 128

PRINT RT 2,B;"R B C D E F G

1210 LET PC28)-0

LET P<36>-0

1220 LET rftov**-0

1230 PRINT PRPER

LET P<29)-0
LET POD-0
LET P*9a«60
1j BRIGHT 1j

INK 7/RT 0,0 j "MOVES-
, 25j "PEGS«";P#9»jRT

»" ; moves j RT
4,0 > PRPER

6

} INK 0; BRIGHT I ) "INPUT
j "99 TO"/RT 6,8; "QUIT, "

;RT 3.0

1240 PRINT PRPER 6; INK 8; BRIGH
T IjRT 9,0; "ONLY ";RT 18,0; "be d
*"jRT 11, 8j H 'fQ hi"
2020 INPUT PRPER 9; INK 7; BRIGH
T I; "MOVE FROM ? " ; LINE F*
2025 IF F*-"99" THEN CO TO 3560
2830 IF F*<1X"1" OR F*<i: i >"8"
OR F*C2X"B" OR F*<2»"H W
THEN BEEP 1,1: print PRPER
2; INK 7t BRIGHT 1; FLASH 1 ; RT
20 .0; "ONLY NUMBER THEN LETTER
e.9. 2R": FOR n«l TO 250' NEXT
TV PRINT RT 20,0; "

" ' GO TO 2820

" ' GO TO 2920
2835 PRINT PRPER 1; BRIGHT 1;
INK ?} FLRSH 1;RT 10, 25; "FROM "j
F*

;v.

SI N( LAIR USER Annual tW4

2040 INPUT PRPER 6; INK ?i BRIGH
T 1 j "HOVE TO ? v > LINE T*
2045 IF T>»"99" THEN GO TO 3360
2350 IF T»C 1 X" 1" OP T*'t 1 >>"e»'
OP Tl^^-fl" OP T*<2>>"H"
THEN BEEP 1,1= PPINT PAPER
2j INK 7; BRIGHT 1; FLRSH ijflT
26, 0j "ONLY NUMBER THEN LETTER
e.9. Eft"' FOR n-1 TO 236 NEXT
Tl< PRINT RT 26,6; "

" : GO TO 2046

2055 PRINT FRPER I) BRIGHT lJ

INK 7; FLRSH 1,RT 12,25; M TO

T»

2060

2078 LET r-CCCODE F*< 1 >-49 >*6 )+<

CODE F*t2>-e4 5

2060 LET t-aCODE T« 1 >-49 >*B J+<

CODE T»<2;>-64)

£690 IF P<f>»6 OR P<t>l THEN

BEEP 1,1" PRINT PAPER 2; INK 7j
BRIGHT 1j FLHSH 1 j RT 26, 6; "
INVALID MOVE "' FOR n»"l TO 256
NEKT n 1 PRINT RT 26, 6 j"

"jRT 10,25.'" "J
_AT 12.25;" " GO TO £020
2106

2110 LET diffv-V<f >-v<:t>

2115 LET diffh-HCf v J-HCt>

2120 IF rfiffh" 4 AND diffv=©

THEN GO TCI 3166

2130 IF dif<ni«-4 AND dlf-Tv=0

THEN GO TO 3266

2140 IF diffV" 4 RND diffh-t?

THEN GO TO 3300

2156 IF diffv"- 4 AND. diffh*8

THEN GO TO 3460

T 1 j RT , 3 1 , " " , RT Ci . k , BOV« ■ RT

0,3©jp«!as

3550 IF Pe3t/1 THEN PRINT RT in
25 }" "jRT L2,25 "

GO TO 2020

3560 INFIJT PflPEP 0j INK ?J BFIGH
T I) FLRSH I /"END OF GAME ■ HNOT
HER ? "; LINE A* IF n*=" M THEN
GO TO 35 60

2160 BEEP 1,1 PR

INK 7} BRIGHT 1.
; " INVALID MO
TO 250' NEWT d

INT PAPER 2j
FLRSH 1 RT 20,6
VE " i FOR n*l
PRINT FIT 20, €
RT 10,25

" i GO TO

THEN GO TO 4060
RT V< t >,HX fe>J "a
" ";RT V P>,H<f

"jRT 12.25,"
. 2026

'3120 BEEP I, 1
3125 IF PK t+1 1=
3130 PRINT INK 2;
" .AT VCt),HCt+l >J
>j" "1
3146 LET F<t>-1' LET P< t+l>"0

let p.-f >=3
3150 GO TO 3506
3220 BEEP 1 1
3225 IF PC t-l >■«
3B36 PRINT INK 2;
%RT V<t> J H< t-l >i
>J " "'
3246 LET P<t>-1

LET P<f>0
3256 GO TO 3580
3320 BEEP 1 , 1
3325 IF P<t+6Js0
"3330 PRINT INK 2i
"j AT V<t+S> J HCt>>
>j " " i
3346 LET P<t>-1' LET F<t+8)*«'

LET P<f >-0
3350 CO TO 3500
3420 BEEP 1 - 1

3425 IF P<t~S>-8 THEN GO TO 4600
3430 PRINT INK 2 1 RT V< t >, H< t > ■ " S
"jRT V<t-a>,HCt^" ".RT VCf'.H'f
>; " " i
3440 LET P<t>l' LET P<t-R}-0'

LET P<:f>-0
3520 LET rnovea.™'**cives + l
3530 LET Pe9i- Prf«-I
3540 PRINT PAPER I J INK ?i BRIGH

THEN GO TO 4000
RT V<t><HKt) ' i
" " f RT V< f J . H'. f

LET PC t-l ;-=0

THEN GO TO 4060
RT Y<t'>*HC't>/"-l

" " i RT V< f > , N< f

3365

:':-rn

35©e

4000

4010

4020
T |;
OVE
PINT
10... 25;
11 ■■ CO

4636

9600 REM

9610

9020

9030

9635

IF R*=- i, 'i'" THEN GO TO 1020
STOP

REM

PRIMT

FLRSH
' i FOP
RT 20,

TO

INVRLID MOVE

PAPER 2;
1 j AT 20 G

n=l TO T50'
& . "

■ PT 12,25;
2026

INK 7 f tfRIGH

INVALID m

NEWT n i P
" .RT

SET UP

DIM

DIM
DIM

P< 64 >

■.-■: i: 4 ■
Ff. 2 )

DIM
DIM

H< S4 )

T*<2>

9050
9060

3676
90B6
, 126.

9100

9110
9120

9130
9140
9150
91^0
917-0

91B6
9190'
9210
9220
9230
9246

9250
9266
V?.7Q
92A6
9290
9300
9320
9346
9356
9360
9370
9380
9390
9406
9410
9428
9430

USR "R"+ri,a

FOR n»6 TO 7

READ * POKE
NEXT n

DRTR £0,126,255,2^5.255,25:
CO
FOR n-1 TO 6

LET V<n> =4

LET V<fl+0> -e

LET V<n+16>«9

LET v;n+24 >^1C

LET V<n+32>"12

LET V(fi+46 >-14

LET 'Atl+48>16

LET yCn+56>*18
NEXT n _p-

FOR n-1 TO 57 STEP 8

LET H<r>) -6

LET W n+1 '=10

LET H<;r»+2>-l2

LET
LET

LET

LET

LET

NEXT

POKE

FOR

HY n+3 >
Hf ri+4 )i

h<: ^+5 )■

H<; n+6 >

■14
■16
■19

■20

H<r.+7>22

23650,6

1-1*0 TO 7

READ
PERD
REI»
READ
READ
HEAD
REAL-
NEXT i

POKE
POKE
POKE
POKE
PC* F
PUKE
POt E
POKE

USR

IJSF

urp

USR
USR
USR
USR

\y r

"C"+T1,C
"D-+ri,d
"E lK +ti,e

■■F"+n,f
"C'+ri.-U
"H" + r..h"
"I M +n, i

9440 LjATR 9,0, 6,0, 127,-54, 1 .. Ub.
0,0, 1, 128,43, l?., l , i£#.8-G,'J< 192,
24,24. 1 ,123,0,6, 7.-24.0.0,5, 160,
0,0,5, I £8^0*0,7*224, 24,24, 1-120,
8,0,3, 19^, 4tf, 1^, ] , 1L-S, 0,0,1, 12R,
i.'7,L'54, 1, 1^0,0,0, 1,0
945^
94€6 RETURN

Sinclair usr:R im«/ raw

87

m

THRTY

WHEN START? is displayed
enter M if you wish to play
first or Y if you would prefer
the computer to start. A set of counters
will then be displayed, four of each
number from one to six. You and the
computer take turns in removing a
number to add to the total. The winner
is the player who brings the total to 31.

Written for the 16K ZX-S1 by J H
Entwistle of Cheltenham, Gloucester-
shire.

3

5*

10

11

12

13

14

lb

13

29

30

35

40

130

110

ill

112

110
113
120
130
140
14b
150
160
164
165
166
167

CLS

PRINT

INPUT

LET

LET

DIM

LET

CLS

FOR N-i TO 6

PRINT N*11U

NB<T H

PRINT FIT 9,0;

IF fl*< 1 >-"V

"START?"

A*
R«31
M*7

LK6,4>
T*0

"TARGET-* 31"
THEN GOTO 220

PRINT AT
INPUT N
LET N-INT
IF NOT N UR

18,0; "NUMBER? 1

RBS

N
N>M-1

THEN GOTO

PRINT m 16,0;"

FOR R»l TO 4

IF [><N,fl>=0 THEN GOTO 145

NEXT ft

PRINT AT N-l.fl-1;

LET DtN.fi^l

LET R*R-N

PRINT AT 9, 0; "TARGET* 31"

PRINT AT 10,0; "TOTAL"" ; 31 -R

IF R«*0 THEN GOTO 340

IF R<0 THEN GOTO 350

170 FOR N»l TO 4

190 IF DCM-l.N)*© THEN GOTO 220
190 NEXT N
200 LET H-M-l
210 GOTO 170
220 LET G~R-M*INT < R^M >
23Q IF R^M^INT < R/tl y THEN LET G
-14-INT (RND*<M-1 >:>
240 FOR N«l TO 4
2S0 IF tXG,N^0 THEN GOTO 300
260 NEXT H

270 LET Ol + INT CRND*<M-1>)
290 GOTO 249
300 PRINT AT G-l.N-1;"."
310 LET R*R-G

315 PRINT AT Ifch 0; "TOTAL *="> 31-R

316 IF R™0 THEN GOTO 3^0

317 IF R<0 THEN GOTO 340
320 LET D<G,N>*1

330 GOTO 100

340 LET T^J.

350 IF T-l THEN PRINT AT 12,0;"
YOfJ WIN. "

360 IF T=0 THEN PRINT AT 12,0.:".
I WIN. "

378 PRINT "AGAIN?"

380 INPUT A*

390 IF A*K I :^"Y" THEN RUN

400 STOP

as

SfNCLAlR USER Annual !Ml

SHFLOW

KAREN CRUICKSHANK of
Guildford, Surrey has sent a pro-
gram for the Spectrum, based on
the workings of the Stock Exchange,
You are given a working week in which
to make as much money as possible by
buying and selling stocks and shares.
Each day you must decide eight times
whether to buy or selJ bonds.

Decisions you can make are based on
the information given, including how
much cash you have in hand and the
market forecast. Beware — your boss
could arrive at any minute and decide to
alter your cashflow situation. It is an
original game calling for planning and
skill. Can you make sufficient money to
be appointed manager at the end of the
week?

LET

1 LET HS=0

-3 LET 5 = 10: LET CFI=lO0fl

5 PAPER 0: INK PUKUEH S3- O

6 F OR iJ=l TO S IF U=l THEN P
RXNT

7 IF U»=2 THEN PRINT

8 IF U=r3 THEN PRINT

3'

9 IF U=* THEN PRINT

10 IF U=5 THEN PRINT
1* PRINT FLASH 1 * "fl HEW UDRKIN
G DHY"

15 POKE 23658,8

20 FOP = 1 TO IS: DEEP 0.05,0;
NEXT O

120 FOR D=l TO 8
122 LET RN=INT IRNO*10J
GO SUB £080
PRINT * *

IF P(0 THEN LET P=0
LET Q^INT mNI>*5>
PRINT PAPER 6; INK 0,

123
225

r>

127
135
136
QRT : " *

137 IF Cfl ? =0

T HAND £";cn

139 IF CR<0
- CFJ

PRINT B;

"REP

FT £
14.0

1*5

THEN PRINT "CASH R
TH^H PRINT "OUERDHft
BONDS AT £";P; " E

'OUERflLL flSSETb £ J1 , IP

HA RK ET FORCfl ST

PRINT

iS) + CR

150 PRINT

IF D=S THEN PRINT -STEADY" :
P=P+-fINT fRNi>*3J -2J
IF Q=l THEN PRINT "CHRNGEfiE
LET P=P> J INT (RMD#23.' -10.'
IF = 2 THEN PRINT "PLUHhETT

LET P=Pt (INT (RMD*50J -i0J
IF 0=3 THEN PRINT "RI5IHG":
P=P+ (INT (RND*50)-15>
IF Q=A THEN PRINT "UNCERTfll

LET P=P+tINT IRHD*60) -3D>

160
LET

LE" :
160
IN©"

LET
195

N! > "
200
210
220
230
2*0

QND5
24.3
2*5
P; '
=50
255
25

BUY?

vR*

TO 50©
TO 200

*-25

AT £"■

INPUT "SELL OR

PEEP 0.05 .,50

IF R$s"SELL" THEN GD

IF HSO'^SUy" THEN GO

LET NS=INT fRND*10S>

PRINT ' ' 'THERE ARE

AVAILABLE"

IF Pw=0 THEN LET P=l

PRINT "HOU MANY BONDS

EPCM 1 '

INPUT X

BEEP 0.08,50
7 IF X>NS THEN PRINT *"I 5BID
,HS, " BONDS NOT ",X," BDNDS 1 ':
LET NSsN£-l; GO TO 2*2

260 IF CA<CA-P*X THEN PRINT "ND
T ENOUGH MONEY": GO TO B4B
279 LET CA=CR-P*X
290 LET B=B+X
295 PRINT ' '
30* NEXT D

30B GO TO 700 ___

5IB LET BU=INT (RNO*2«0) *50
515 IF P{s» THEN LET P=l

PRINT '"MARKET PRICE £. ' ; P
PRINT BU; " BUYERS WANTING B

PRINT "HOU MANY BONDS TO SE

INPUT S

BEEP 0.09,50

IF 5>BU THEN PRINT ' * *' I SRI
BU;" BUYERS": LET OU=BU-l G

525

IF S)B THEN PRINT "YOU HAL'E
THAT MANY BONDS": GO TO 530

IF 5<0 THEN GO TO 525

LET CR=P*StCR

LET B=B-S

PRINT ' ' : NEXT D

FOR O=-30 TO 30

PEEP 0.005,0

NEXT O

IF U < >5 THEN PRINT ' THE

OF THE DRY 1

IF U=5 THE N PRINT

"J Cfl

PRINT B; " BONDS AT £",P
PRINT 'TOTAL ASSETS £*' ; LE
IP*BJ +CA: PRINT O
IF U=5 THEN GO TO 7*9
IF 1NKEV*="" THEN GO TO 7*5
CL5 NEXT *

XF O<0 THEN PRINT " YOU'RE
* I t i i ■*

520

525
ONDTb

530
LL?"

5*0

54.5

5*6

D ";

O TO

550
N'T

555

560
595

700
705
7©5
710
END
7 IE

720

730

7*0

T O-

?4S
747

FIRED

750 IF O>0 AND 0<^^f»^ THEN PRIN
T "YOU DO NOT USE ENOUGH INIT1AT
IUE"

765 IF O>9000 AND Of 25000 THEN
PRINT "PROMOTION TO HERD CASHIER
t i ■*

D>25P00 AND D(45000 THEN
PROMOTION TO CHIEF SUPER

770 IF

PRINT
UISOR"

775 IF 0>HS THEN LET HS=0

780 IF O?*5000 THEN PRINT
rlRNAGERS SEAT AUATTS YOU"

785 PRINT '"HIGH SCORE £"

'THE
HS

PRE S S ANY

-90 PRINT * * * "

KEY"

S00 IF INKEYS-" " THEN GO TO B00

510 CLS GO TO 2
2010 IF RN=1 THEN PRINT ' ' "SUDDE
N DEVALUATION MRS MEANT": PRINT
"THHT TWO BONDS ARE BEING MERGED
" : PRINT "INTO ONE - IE I CUT IN MA
LF"

2020 IF RN=1 THEN LET B = INT tB^2
i

2025 LET C=INT (RND*3)
2030 IF RN=2 THEN PRINT ''"BOSS
15 COMING AROUND CHECKING.": PAU
SE 100 : XF C-0 THEN PRINT "HAD Y
DU WORRIED i ! "
20*0 IF RN=2 AND C=l THEN PRINT

HE CUTS OFF YOUR CRSH SUPPLY BY
" : PRINT "HALF. tHR # HA,HBJ" LET

CR=Cfl/2
3350 IF RN=2 AND C=2 THEN PRINT
"GIVES YOU EXTRR 10* BONDS."': LE
T B=B+100
2100 RETURN

; AIR USER Annuel 1984

10

30
35
40
43
50
<S0
65
70
75
80
95
90
91
ERGY"
95 LET

GOSUa 1000

CLS

LET U-0

LET SH*1

LET T*30

LET S-0

LET 2-3

LET R-25G

FAST

PRINT AT 1,

FOR L«2 TO

PRINT "C is 30*sf ^is > M

NEXT L

PRINT AT 20, 0j u <32*ls>"

PRINT FIT 0,0j " EN

0j M <32*is>"
20

100 LET
105 FOR
110 LET
115 LET
120
125
127
130
135
l-»7"
140

145 PRINT

O10
S-10
n*i TO T

tf^INT <RNC-*18H2

Y-INT <RND*29H1

X,YjCHR* 23

PRINT RT

NEXT R

SLOW

PRINT RT CBj "(flh> (

LET C-C-K INKEYf^S 1

)

LET 6»*B+t INKEY**"e")-( INKEY

)-< INKEY

150
PEEK
155
16©
166

RT r B ■

LET P-PEEK CREEK 16398+256*
16399)

IF P*23 THEN GOTO 200
P=128 THEN GOTO 220

IF

IF

P^CODE ,, C9h>" THEN PRINT

RT @,Wj m m

167 IF P-CODE "C9h>" THEN LET U
■41+1

168

170

160

185

190
M UUU"

195 GOTO

IF W-10 THEN GOTO
IF P-5S THEN GOTO
PRINT RT C*9i "0"
LET S-S+l
IF S>R THEN PRINT

230
500

RT 20, 10;

X

"GRME OVER",iTR

"YOU RRN OUT
SCORE-" jS

130

200 LET 2-2-1

205 PRUSE .3

210 IF Z*0 THEN GOTO 220

213 GOTO 130

220 PRINT RT 2, 1
B 20 r "SCORE-" ;S

225 STOP

230 PRINT RT 2, 1
OF ENERGY"; TAB 15

235 STOP

500 CLS

510 PRINT "YOU COMPLETED SHEET
"jSHjTRB 20i "SCORE-" tS

513 PRINT "LIVES-"; 2

520 PRINT "MORE OBSTACLES WILL
NOW RPPERR"

525 PRUSE 200

530 CLS

535 LET W-0

540 LET T-T+30

345 LET R-R+175

547 IF SH>*3 THEN LET R-R+125

550 LET SH-SH+1

560 GOTO 65

570 STOP
1000 PRINT " MOLE"
1010 PRINT RT 2,0; "YOU STEER YOU
R TUNNELING MOLE, RVOIDING THE"
"*""ftND YOUR OWN TUNNELS" "< G
hp"".IF YOU HIT ONE OF THE" ,t U" ,T S

YOU CRN GO ONTO RNOTHER SCRE
EN. "

1023 PRINT RT 7,0; "IF YOU HIT R"
"••"YOU WILL LOOSE R LIFE."
1030 PRINT RT 9,0;" IF YOU HIT TH
E BORDER YOU LOOSE RLL YOUR LIVE
S. w

1040 PRINT RT 11,0; "IF YOU HIT Y
OUR OWN TUNNEL YOU LOOSE SOME
F YOUR ENERGY. THE SRME IF
YOU STAY STILL. "
1050 PRINT RT 15.0; "CURSOR KEYS
TO MOVE. "jTRB 10; "PRESS fl KEY."
1060 PRUSE 4E4
1O70 RETURN

STEER your tunneling Mole
through the ground. Hitting a
stone will cause you to lose a life
and hitting the border will kill you. If
you remain still, or hit your tunnelj you
will lose some energy. Eating a worm
"V" will move you to another screen.

The program was written for the 1 6K
ZX-81 by Simon Reeve of Chess in gton,
Surrey.

Graphics instructions are given in
lower-case letters within brackets. A
space is represented by *sp*, a graphic
character by *g', and an inverse charac-
ter by V. Thus 'gh' represents graphic \

n Jh.

90

SINCLAIR USER. Attmtai J9S4

SINCLAIR USER Annual 19S4

a

[ J; ■

l «-->•

."■**-•-

r* .v-:3

?>

10 GOTO 40

28 LET S=«S+C-<E*4>

30 GOTO 60

40 LET fi-CODE "C92>"

30 LET S«CDDE "COS "

60 LET E^PT-PI

70 LET OE

80 PRINT AT 0,0j "CREDIT »";S;"

H ;fiT 1,0j "MINED *"iCj" %"DEP
TH "jE;" "

90 IF S<0 THEN GOTO VRL "300"
100 IF E>20 THEN LET fl-8
110 IF INKEY*- 1 '?" THEN GOTO 20
120 IF IMKEY*=»"6" THEN GOTO VRL
"IS©"

130 IF INKEY**"S" THEN GOTO VRL

"400"

140 GOTO VRL "90"

130 LET E*E+PI^PI

160 IF INT <RND*C0DE "-" >>R THE
N GOTO VRL "200"
( 170 PRINT RT CODE "< 93 >" , 0j "GQL

180 LET OC+1NT < RND*CODE "C9s)
" )+CODE "C9s> Nt

190 GOTO 90

200 IF INT <RND*160/RK>CODE "?
" THEN GOTO VRL "240"

210 PRINT RT CODE "< 93 >" , 0j "EXP
ip

220 LET OC-CDDE "COS M
230 GOTO 80

240 IF INT <RND*10>O5 THEN GOT
VRL "160"
( 230 PRINT RT CODE u <«5 V , 8j "COR

260 LET C=*C+INT <RND*3>+1

270 GOTO 80

300 PRINT "BANKRUPT"

310 STOP

400 IF EO0 THEN GOTO VRL "90"

410 PRINT "PROFIT**"; S-2Q0

■ ■ i «<

*m\\ *

J J

/

/

\>

OU STAR J with S200 in the
bank and your aim is to make as
much profit as possible from
your mine, h costs you S4 to dig one-
metre and each time you return to the
surface your Funds are altered to take
account of your profit and expenditure.
You may find coal (coa) or gold (goJ),
or you may be unlucky and be involved
in an explosion, which will cost you
$200, Key 6 moves you down the mine
and key 7 returns you to the surface.

Mark Evans of Welling, Kent wrote
Miner for the IK ZX-81.

92

SINCLAIR USER Annual im

p ■ ■.,■

p

HIUP HARPER, aged nine, df
Benfleet, Essex sent Ski-Run for
the 16K. Spectrum. Manipulate
your skier round the flags using cursor
keys 6 and 7. You have 10 lives in
which to complete the ski run as many
times as possible.

It is an ideal game Tor people who
find that manipulation of characters by
the use of four or eight keys is, as yet,
beyond them.

4 Graphic S, graphic F

5 Graphic L

— //5-

X •

REM 'SHi": CL5

/\ 2

LET S I

= 10. PRINT

FLH5H 1,

IN

4 K\ 2 J

PftPER'

6 ; AT 1 , 5 ;

PLEASE STOP

THE

TAPE" :

PR INT RT

2 ,

3;. "'Press

any

Key \o

con l inue"

: PAUSE

3

CLS .

GO SUB 1000

4

PRINT

AT 1,13,"

SKI

" , "SK i

i S

a ga*e o F

skill and

i t

is* 1 ; "

3 IS

■3 very addictive.

/

Jse

Keys 6

St 7 to steer

your

" ; "s

(iier, iJiJ ,round the

f lass ,

-J«

» *

YOU

hawe got

10

I i ves !

* k _

INK

1: PRINT ; PRINT

i

PRINT

M

Press any Key to continue": prus
E

5 CLS PRINT RT 10,0; "SKiers
Left"; : FOR f-S TO STEP -1: P

RINT INK l; "_fc "; : NEXT f: IP s = -
1 THEN GO TO 5000

6 LET a = 1 : BORDER 5 : PAPER 7 :
INK 2

7 PRINT BRIGHT 1; PAPER 7; IN
K 2,HT 1,0; - fK '^

C ^.i,"/*"" a ' ( ; BRIGHT 1;
7; INK 2; '

°APER

B PRINT RT 3,0; INK 0. PAPER

RT

*,0;

PAPER 7,
0,0. INK

-■

0J PAPFR fi

—

9 PLOT 0,0

DRAU

255,0:
DRRU

DRAU
-175

PRPER 7; IN

BEEP

PAUSE

0,175: DRRU -255,0
10 FOR f=l TO 31

30 PRINT BRIGHT 1;

K I;BT a , f; "i"

31 IF <a=u RND [ (f=6) OR if-1
3) OR If =273) THEN GO TO 3000

22 IF 13=2) AND t i f =4-X OR <f=A

3) OR if=22) OP (f=31)J THEN GO

rO 2i eEEP . 002 , r - print rt a , f ;

^iiTBT'a^^NKEV*:^- AND a ,2

}-IINKEY* = "7" AND a>D
30 NEXT f

35 LET g^-g+1 _ . _-.„

4.0 PRINT FLASH l; PAPER Xi INK

50 BEEP .1-5: PAUSE 5
,6: PAU5E 5: BEEP -i,S ;

BEEP .1,6: BEEP . 3>B
&0 GO TO S
1000 LET g=0i FOR f =0 TO 7

I: POKE USR "S"'+F,Z: NEXT
1010 FOR F-0 TO 7: RERD Z:
USR '*f" + f,Z: NEXT f
1020 FOR f *0 TO 7 : RERD z :
USR "l" + f t Z: NEXT f
1040 FOR f =0 TO 7: RERD Z:
USR "e-J-f.Z: NEXT F
1090 RETURN

3000 DRTR BIN 0001 1000- BIN 00011
000, BIN 00010000 ,B IN 00011111,61
N 06011010, BIN 00011010, BIN 0001
0001, BIN 11111111

2010 DATA BIN 10000000 .BIN 11101
111, BIN 11111110, BIN 11111100,61
N 111H110 J BIN 11111111, BIN 1000

0000, BIN 10000000

2020 DATA 255 ,0 . j . ,0 .0 ,£55
204.0 DRTR 0,0,0, BIN 01001001, BIN
00101010,0, BIN 00101010, BIN 010
01001

3000 FOR q=0 TO 7: PRINT
1; PRPER 7; FLASH 1; INK
P*7 3 ; RT

RERD
f

POKE

POKE
POKE

f;

,3

=s
= g

E

0,
U

B,

cy

5S55 PRINT RT 1,1, "You
«i th "; y; " runs"

5078 IF INKEfY**"'y " THEN

T S=10: GO TO 5

50S0 IF INKE^fs"n" THEN CLS

TD 4000
S090 GO TO 5070

BRIGHT
INT (RN

3010

BEEP

- 1 , -4.5 : NEXT Q

3015

LET S

=s -1

3016

LET 9

=g +1

3020

GO TO

B0

■1000

STOP

S0&0

PLOT

0,0: DRAU

255,0:

DRAU

0,175: DRRU -355,0:

DRRU 0,

-175:

PRINT RT

6, 7; "uan t

another

SO?"

,RT 7

7 , 13; '■

Cy sn ) "

( i ni shed

CLS

LE
GO

n

SINCLAIR USBR Annual I9S4

n

AIRLINE A *«ig and a praynr •■
not be enougm to turn your F3
m*cn to £33 million in ihe dms

a*j-*j. tut you* ri;\arVMi wizardry

mM enable you Id lake over Bndsr.
Airways. or w# <? Bur* en 2X&t

16K - £5 and Speclrum T6K/4BK
re

CORN CROPPER
drougHte ars two of the problems
laang ine tarrner Planting tartih/mu
and harvesting must all be done
aconomicaJly if you are to reap the
rewards onared im corn copper
Runs or. ZXftl 16K — £6anxJ
Spectrun- 'QK J9K — £6

AUTOCH6F I u lavs a milkjn *n
capital end need lo increase Ihts to
C25 mien in ih« shortest Nn^
potable Inflation s1n*.e?, sluggish
markelB ars only some ol !hc
hazards lo overcome Runs on
ZXB1 -6K - C5 andSjMCtfum

SMUGGLER ■'■ -«tterof a ' -

century vessel you plough between
England and tne confcnent vi&liriy
noris to buy and sen your cargo.
CM beware tf* customs men.
pirates and safe force winds can all
run you aground Hun* on
Speclrum 4BK - £6

DALLAS j

t

:

Q£ rjTrnTcnif qamo

3u amass enou_
petro drtlara lo' lake over Ir* l' jiug
rjniEiire Oil throat buensss and an
eye lov ihe maui chance may gfl<
you Ihere but you II need nerves d'
steel lo become Itw cul lung ol
Dalto Runs on ZX81 16K - £&
and Specif i. rr- 1SK.4HK re

PAINT SHOP In t-' nl shop ere

■ Hasng and
quoting wthin 1h»s'lime limit wiM lesl
your business aCumtKi lo the luf
and weekly balance sneets wiH
pfOvB Ihe quality U* yuui dscison
making Runs on ZXS1 lflK - £S
and SpeCtriirw 1SK.'4SK - £0

PLUNDER i, i- ,-.:. ':ioe the King
ol Spain's beard Engage I hfi
Spanish thlpt ::r- \tm tugh seat
survive lhe>i broadsides and
ptuntfer the gold destined frx tJia
Armada and you might get yuut
Kmghrnrxxl before francis Dra*e
Runs on Speclrum 4SK - £fi

GANGSTE H Are you cold nea/led
and caftan?, enough ki wci'iani ihe
1iMe 01 Don Yov need lo be rl you
are lo rise lo the loo or |tw mlf* A
Quick luftyar tMipjer and a/i even
quicker brain are needed 'O control
1tve mofcs and their rackets Runs
on SpectrL.' , ■■ .t- J .H. Ffi

BRITISH LOWLAND You are »y*n
a racing sun im yOuf sinai spoHs

, pul you nave an
owerdralt to repay and a workforce Id
*jw kept happy Sleer yout way to

BUOOWS *tlh CStoTi.iI management
and indusi'iJ relations Runs on
Spaetrv 4HK ffi

awaiting tne toothartfy and caratess
•OVamuror There are many bndgea
and many monsters W* youba the
on* to mafia the Abyss safe to ocas

again Runs on Spectrum *8K f ■'.

STTE Comptetfi Ihe tan ovcuM you

need lo txnid your computer system
than raium home Easy Byte haa
senl rilt AkK.ii one inonslers lo herry
you through' 1t>^ tiree ctmanacn#l
maze of circu<r¥.. it any of Ihem
Catch you Runs on Specli urn
■flflK EE

Camelot

h* baniBnscl *nnu<

Pandragon you

must fmd seven

wagwaans mar utrv m your way
undmaktt a tnumpriant return lo
Camatot 1o be crovmeO King I
On 2X81 16*! - £5 and Speclrum

Available from W H Smith. Boots, Rumbelows and all good computer shops or
Cases Computer Simulations Ltd., 14 Langton Way, London SE3 7TL.

<x

Strategy Games.

're no pushover

AIRPLANE simulates an aero-
plane flight from London to one
of 10 airports round the world.
The screen displays your control pant I,
complete with information about speed
and course.

You are given the opportunity to
change your speed, height and course.
If you choose not to alter any of them,
enter ''0", Keep your changes within
the defined limits and look carefully at
the readings displayed before making a

change. You have no second chances
and a slight mistake will lead to a crash.

The program was written for the 16K
Spectrum by David Court ier-Dution of
Bradfield, Berkshire.

1 LET s-=0 LET x-0- LET *-B

100 130

2V® 250 300"

PRTE"

LET s-B

24B PLOT 99,

L6 DRAW 0, 15&; PLO

318 PLOT &9,95' DRAW 166,0- PLO

IB GO SUB 1020

T 0, 144 DRRW

233,0

T 0,160' DRAW ee,0: PLOT 89, 112

11 GO SUB 9508

550 PRINT

AT

1 4 . 1 i

INK Ij'OLTIT

DRAW 166,0

15 LET m-l LET tr=w BORDER $

UPE"

340 FOR t=32 TO 126 STEP 16 PL

PAPER 7< INK 2

251 PRINT

AT

18, 3j

INK I j "RANGE

OT 0,t- DRHW S6,0' NEXT t

20 PLOT 89.143 E'RRiJ INK 3j?,«

■ a

350 PRINT AT 21,4 "

PLOT (99+INT l/tft>«14S' DRAW I

232 PRINT

RT

2,2;

INK 1 J" 1 SPEED"

" ' ovep ' co sue

HK 3; INT w^50,0

253 PRINT

AT

e, ij

INK If "TIM. F

700

30 PRINT 0T 17M5j "DESTINATION

LAP"

528 IF s<150 AND *>0 THEN CO TO

"

254 PRINT

AT

0,0,

INK :?- "INSTR'J

3000

100 LET a*0 LET ft-0 LET d-0

ME NTS"

540 PRINT AT 3, 13 ; " Intr«*s* 'Oec

LET r-0 LET c-0' LET f-29 LET

255 PR TNT

FIT

12,0,

INK 1j"RUNWP

reus*"'; AT 6* 13 j "thru at +7TV-73T"

n-0

V LEFT"

368 INPUT * IF *>73 THEN LET N

200 OVEP 1 INK 2 PLOT 0,0 DP

236 PRINT

RT

18,0,

INK l.;"FLRP

-73

AN £55,8 DRAW 0,175' DRflW -253,

ANGLE"

563 IF x<-75 THEN LET x*-7*3

0: DRAW B, -175

25^* PRINT

RT

0,1;

INK If'&BBm

570 LET s-&+* LET c-* LET x-0

210 PLOT 0,16 DRAW £55*0- PPIN

INC"

IF a>600 THEM LET *-68B

T AT 20,0; INK 1, "FUEL"
220 PLOT 32; 0- DRAW 0,16' PLOT

233 PRINT

ROTE "

HT

4.0.

INK ii"'ACCELE

372 LET s-*-3 IF *<0 THEN LET
**0

32, S DRAW 223,0

573 LET l-t-INT < 1 .25*< **C l-d^l

230 PRI.NT AT 20, 4; INK 3, "0 50

;■*:■? PRINT

RT

le, i.

INK I J "DROP

00 > > >

SINCLAIR USER /Imrua/ /0M

9?

I

575 GO SUB 700

579 IF *<130 FIND *>8 THEN CO TO

5O&0

560 LET x-0: PRINT AT 5,13;"Cha

n9* f 1 *P amB I •? " .► AT 6 , 1 3 j ji 50^-50
" INPUT »' LET n»n+v
IF t>>50 THEN LET n-50
301 IF n<-50 THEN LET n— 50
582 LET a-*+INT C3.06*-n> ; IF a<

-5 THEN GO TO 5020
363 IF a>^500 THEN LET *-508
505 IF *<4 RND 1>10B THEN LET *

-0

590 LET r-INT C 3. 06*n > ■ LET *-m
*-ti
595 IF a<0 RND »>— S THEN LET *

-0
6.80 GO SUB 700
605 LET ZK"1

610 PRINT AT 3, 1 3 j" Alter tail f
laP? "jRT 6j 13 J ■+45^-43" INPUT

■*< LET d-d+T' IF Pe>179 THEN LE
T Pm- 179

Sl2 IF P*<-1?9 THEN LET Pe-179

620 LET Pe*Pe-d

630 IF l<-0 THEN LET U"W-»

635 IF f<-0 THEN GO TO 5040

640 IF *<0 FIND 1>0 THEN GO TO 3
BOS

643 IF *<-0 RND P*O0 RND K-25
THEN GO TO 5100

660 LET f-f-INT C< iVl0+s^20 V <
r-'ZSV IF f<-0 THEN GO TO 3040

678 IF l>408 RND H300 RND *>5
RND a<30 THEN LET a- 100

673 IF i>230 AND *<-0 THEN LET
a-50

eae if u<-0 then go to 3060

700 PRINT RT 3v1j INK 0j»j"
RT 13. 1)*) " '" >RT lM-li" "JRT

?,l>di» "jflT 19,1**1" "JHT 3,
lio" "jAT iTtltri* "jflT 9,liP
■j" "jRT 13>ljyj " "

810 FOR t-16 TO 144 STEP 16' PL

OT 0,t- DRAW B6,0 NEMT t
060 PRINT RT 8, IE, INK 4j M -

R^BERRING +"
800 PRINT RT 9, 12* H

II

090 PRINT RT 9»*iJ"0*< PRINT RT

9j21-INT CRe'Sfe^ "•*•"

092 IF X*O0 THEN GO TO 900

093 RETURN

900 PLOT INK SjINT CCn-lV30)+8
S. INT */ie+146

905 LET 2W*0

910 PRINT RT 21 ,ft" "

920 IF aOQ RND i<t>-0 RND f>0 AN
D P0-0 RND U0 RND s<-0 RND S>--
1 THEH GO TO 6000

933 IF a<-40 THEH PRINT RT 16 , 1
3J INK 2j PAPER 7; FLRSH !,"RLTI
TUDE"

940 IF *<165 THEN PRINT RT
3; INK 2 J PAPER 7) FLf
D"

945 IF K100 THEN PRINT RT
5 J INK 2> PAPER 7, FLf
E"

930 IF 1OO0 RND P*<>0 THEN PR I
NT RT 13-15; INK 2; PRPER 7> FLR
SH J j "R^BERPING"

953 IF u<208 THEN PRINT RT 12,1
3 J INK 2; PAPER 7 J FLASH 1j"RUNW
RY LETT"

960 FOR 1-1 TO 10O : SEEP .007,-
22: NEXT <! ■ FLASH 0' PRINT RT 12
,13r "iAT 13, 15J"

"jflT 14,13>"
";AT 15.15j" "i

RT 16., 15 j"
1000 GO TO 500
1020 PRPER 8' INK 3^ BORDER 2 C

3..

,e,-3

3,3 BEEP .3,3
0' —2

'-7 TO 5 SEEP . 1 -m M
EHT pi PAUSE 20 BEEP . 17", 15 PR
USE 15 BEEP .4,-23

.3,0- BEEP

1050 BEET .

.3,3' BEEP

1060 FOR m

I4j1

I "SPEE

12 1

1 j "RANG

1070 PRINT RT 10,12, INK 2j ,| RIRP
LANE" PAUSE 130' CLS
1000 PRINT " HIPPLRNE simulate*
■sin. a i roP t aircef 1 1 9ht from London *

irPort to one of ten other air

Port* *rouridth* world, th* choice
of which liMotirj,Hokwv»r- flwiiro
* Plan* is not as easy ** *ou *

asi think, so read these instruct*

oti* carefully"

1100 PRINT ' " > " ", FLRSH 1 , "

PRESS ANY KEY TO CONTINUE"
1120 IF INKEY*-"" THEH GO TO 1 12

1130 CLS PRINT i FLRSH 1 , "BERP
IN MIND" j FLRSH B> ' "You ulU *t
all at under 130 KMH io do Tiot t
ak* off b*fo^* t^l* sP##d H at
tained"

'To chanfl* lltitudtf
< up 5 or ne 9 a 1 1 we ( d
Mu.it b* applied to
m our a 1 1 i tu <2* uill
thr#e tines, th* f 1 1

'To altar court* u*e
FLRP^iJhe'rt th* runi»ia

CR.--BEAPINC;l 14 -<0

LS

1O30 PRINT RT 10, IBj "INSTRUCTION

I033 IF INKEY*-"n" THEH RETURN
1036 IT INKEy*^"" THEN GO TO 103
5

1140 PRINT
a Positive

QUft'J V.l 1114-
th* nap*;
chaioQv b«
p ana I » "
1150 PRINT
vour TRIL

W b€- ? r- 1 ri'S

v will be on"

U55 PRINT "course. 1ft the R^BERP
ING dlsPlau vQvr d«-atinaticin is

represented b^ 'o' and vo'jr netti
al course b¥"

1159 PRINT ■"-*";whe-n the 'o J dis
UPPears aouwill be on course"

96

SINCLAIR USKR Annual 1$S4

/TV

" . FLHSH 1
CONTINUE"
■ "■ THEN GO TO

"PR
117

lies PRINT ' i "

ESS ANY KEY TO

1170 IF INKEY*'

lie© CLS : PRINT "Your speed wil

1 decrease 19 you cllnb and iner

hu n aou decendOue tc *ir res

l stance It tfill decrease bu 5

KflH cftar ever* set of ins true

tions"

t 1 90 PR I NT '" The RUNWAY LEFT ref

ers. to *ou.r destination and if

this value- tsl*** thsn you -uil

1 -ra»h. "

1200 PRINT '"Your Position rel*t

ive to Londonand your de*tir>atio

n- is P toted at tr.* to* of the *

cee/i to thou your Fas it ion at a

9lanee.Th*> distance sou are fr

O^i «■ destination is *hou'

n in the RANGE readout"

PRINT I ' "'
ANY KEV TO
IF IKHCEY*" 1 "'

" - FLASH 1 ; "P
CONTINUE"

THEN GO TO 123

1220

ffESS

1230

I

1235 CLS : PRINT H To I ar.d suctes

•■fultu your speed must elual 0^

our altitude mutt **lual 0, and s#o

'UST be on the riinwaa"
12*0 PRINT '"Flashin* imstructiO
ns uil I half »OU to f"l* the Plan
« safely. GOOD LUC

Kl"

1230 PRINT ^ TNK 6, j ' ' "TO REPEAT
INSTRUCTIONS PRESS 'R J PRESS fl
NY OTHER KEY TO BEGIN"
1270 IF INKEYl-'^r-" THEN CLS ' GO

to 1000

1580 if inkey»-"" then go to 127

8

4000 RETURN

5000 PAUSE 40 CLS ■ PRINT "You
stalled at "imt* VSWH and c
cashed -USELESS" GO TO 13200

5020 PHU8S 40 CLS i PRINT "Your
altitude is "j|<" meters so you
have crashed -USELESS"' TO TO 5

2M

5B40 PAUSE 40- CLS ' PRINT "You

ran out of fuel so uou have era

shed-USELESS" > GO TO 3200

5060 PAUSE 40- CLS ■ PRINT "You

over shot the run wan by "jRSS vt

" meter 1 * so aou have crashed -U

"5ELES3" ' GO TO 3200

5080 PAUSE 40 CLS PRINT "You

tri#d to land "il," wiles short

of the runway so mod have cr

Jtshed-USELESS"^ CD TO T20P

5100 PAUSE 40 CLS : PRINT "You

h*ve Missed the runway conPlft^l

w bu "ip»." decrees and have era

*hed -USELESS" GO TO 5200

3200 PAUSE 300 CLS i PRINT "ftno

the-r f liatitTCu^-n)" ' IF INKEY«-"s

" THEN CO TO 1 STOP

5300 GO TO t

CO00 LET k-lNT ?s3

6092 Ltf-K». INT < 1 1 0*< w^ y tr } >■ LE

T k"<2*v -'+sc

6100 PAUSE 100' CLS PRINT "Wei

1 done'Ynij. icorifcl "'TNT fe;" Poln

ts out of * Possible iOB" ■ STOP

0100 "TOP

9500 INK 7 BORDER 2' PAPER 0' C

LC PRINT "WHICH AIRPORT?" ■■ PRI

NT "0 5Istanbur , '"l >Chica*o"" "2 >M

i I an "' " 3 JMos c ow n ' ■ 4 >Ne-,« York 5

)Fort Stanley 6 X)slo" J "7>Tei A

wfev >Delhi 9 Toronto"

9583 TMK 3 PAPER 7

9310 IF INKEY*-"1" THEN CO TO 96

00

9528 IF lNKEY**-'2" THEN GO TO 96

20

9338 IF INKEY<~"3 ,> THEN GO TO 96

40

?540 IF INKEY*-"4" THEN GO TO 96

60

9350 IF INKFY*=="5" THEM GO T 96

00

9360 TF lNKEY*-"e" THEN GO TO 57

00

9565 IF IWKEY»-"8" THEN GO TO 97

20

9570 IF rNKEY*-"7» THEN GO TO 97

40

9375 IF IHKEY#»"«* THEN GO TO 97

60

95« IF INKEY*-"3" THEN CO TO 97

@@

9583 GO TO 95I0

9600 CLS LET l-<235 LET e-19
LET u«700 LCT Pr-=170 PRINT AT
lij. 16> "CHICAGO" PETijF'i

9620 CLE ' LET 1-381 LET *=4 L

ET u-700 LET Pe=S3 PRINT AT iS

, 16 -MILAN" RETURN

9640 CLS LET 1=154?- LET *-9

LET ij-640 LET P«— 10 PPINT AT
IS 16 "MO ■SCON 1 ' RETURN
?660 CL^ LET 1-3508 LET e-13
LET ( ,i=730 LET Pe-J70 PRINT r
T 13, 16. i" NEW YORK"- RETURN

9690 CLS ' LET 1-74 OS LET e-24

■ LET w-440 LET r.:-'110' PRINT R
T 10, 1.6j "PORT STANLEY" ■ PET UP' J
9700 CLS LET 1-732 LET e-5 ■
LET u-300^ LET {>#— 3P PR I « IT AT
10, 16 "OSLO" RETURN

9720 CLS 1 LET 1-1362 LET e-9
LET w-4B0' LET Fe-35 PRINT AT
19, 16. " I STANBUL " : RETURN

9740 CLS ' LET 1»2230 LET e-1 1

■ LET w-650 LET Pe-40 PRINT AT
IS. 16 i "TEL AVIV" PETURN

9760 CLS LET 1-3203 ' LET e-1 8

LET w-310 LET Pe-34 PRINT AT
10, 16j "DELHI" RETURN
?7i30 CLS LET I =.3720 ■ LET e-1 4

LET tj=«35g LET Pe— 150 PRINT
AT 10, 16; "TORONTO"- RETURN

m

SINCLAIR USER Annua! !9S4

97

Everyone wants to
hands onThe Fuller

*~«>?

<s0@>

The Fuller gilt pack has got to be the
computer bargain of the decade, no wonder
everyone wants to get their hands on one

This super girl pack contains the fantastic
Fuller Master Unit, the ultimate unit thai
provides all the requirements for the serious
games enthusiast The Fuller Master Unit
incorporates both the Fuller Box and Orator, IB
anwing features include a speech synthesiser,
an independent sound synthesiser, a joystick
interface an amplifier for standard Spectrum
sound, a cassette interface and a in h socket
The pack will also include a Master Unit demo
tape and full documentation

As well as the Master unit this Gift Pack also
contains a de luxe Joystick, with suction
adhesion, a firm smooth action and a moulded
hand grip incorporating twin firing buttons

once your ipectrum has been added to the

computer system that is second to none.

Now you can pit your mind against the four
unique, exciting computer games included in
the pack. These games have been especially
adapted for thts superb system and have ad'
arcade sound effects and speech to bring out
the very best in your Spectrum

The Fuller Gift Pack saves
you L20 on the purchase P #fl fl

price of buying these items T / U V
separately. aVf 17* v

Power to

All kry* i>n
ihv ms keyboard
ntntrtin all The
GiaphK i ha i deters
ol Ihv IX Spectrum

f

SKLL

MICRO

SYSTFMS

et

Fuller Micro Systems

The ZX Centre. 71 Dale Street,

Liverpool 2. Tel: 051 236 6109

■111 Full"

*lk in Syslrmv

wf itnw !□

in fini I din Ihc

hi(|hcs(qudlilv

in both rfwdrrh MM

(IrwIlil^rl^Til irh^inmij

tiui pradurl!h Air Ih* vm

ttrii UY hnnv iin* hull! ii

til. Hill I II* IL.1'1 111 lift

df pdrtnwnl In cfisuif chip MNh I

iidtmlhir wiylh'tl Omitnik

include rf tiill larwv nl mnnHinrnu

:iin| kilt rh,n will iTiithf thr mini <»t hiui

f«dlrnl irpul«linii ffii n'luthiliTv nisi
i iinv ,t world wide iw vi.n igudtdnlri'

Transform your Spectrum with the FDS
Keyboard and Feel the newly acquired power
flow from your fingertips as you enter data
lightning fast accuracy.

The Fuller TDS Keyboard has been especially
designed for the professional user This etega ~
slimline, desk top system has a keyboard that
inclines toward you and contains ail the grapt
characters of the IX Spectrum, plus, additional
function keys, shift keys on either side and a
space bar With all the entry keys double sue,
lightni ng 1 asl . accui a I e da I a e n I ry is now made
easy. Other amazing features of the FDS
include -

Cold plated key switch contacts, guaranteed to
to 6 operations 4 cursor control keys. 2 hinctioi.
tor direct entry into F mode - ■

Based on the popular FD42 system, the Fuller
f[)S is simple to install it requres no soldering
or technical knowledge For the user who is
reluctant io install his computer circuit board
inside the FDS. a butfeT is available i£ft 7S +
sup&pt which simply plugs
into the expansion pon P/ffl f|E
and connects directly w LLU -M ■

to the, keyboard fc IJrJi/

Hinndtivr mlnlMC I
t iiiiy dddpTCd
rci til imn1r
the (&w

WHHflim ■ ■ ■

Please supply me with TDS Keyboardist

I enclose a cheque po FuMr Qin PdrkpV

payable to

Fuller Micro Systems tor ...._ or debit my credit card,

Card No I I I I I I

HUD Q Barclaycard

Signature „.„J3.* CC ™

Card

Name ....
Address

Fuller Micro Systems, The ZX Centre,

71 Dale Streel. Liverpool 2 Tel: 051 -236 6109

1 REM ** RODOT HUNT **

i LET bscr'Q ■

4 LET hit--a

5 LET «*n*=3 LET «*-"ics^t^

10 LET K-13' LET ¥-10 < LET a-1
5 LET b»lQ

11 LET ftCT-ti LET nw-0
15 SUfttCR t

17 CLS

20 PR INI AT B,e; "cceec ROBOT

hunt ftcr - mem-

2B FUR |-1 TO 20' BEEP . 1,RNM

ae

31 LET t¥-KNt-#2Q+i ■ LET tx-RML>
*3l IF RTTfi < ta - tx ?< >36 THEN GO

TO 31

JS PRINT FIT tu,tx; INK 4j;X'"

NEKT i
- 'J's 00 TO b5

30 FUR i-l TO £1' BEEP .l.fiNOt
30

31 LET t-< «RN&*2Q+ 1- LET tx-RND
Jfcil IF RTTR <t*,tx><>36 THEM GO

TO Si
52 PRINT flT Uotxi INK 4 , " i * ■
NEXT i

33 LET t3tv»0

CO LET h-INT <RNt»t£0>+l' LET I
■INT CRNW30' ir RTTR <h,U<>&6
then .(j tu 00

: L LIT hi-*v LET li-L' LET m&-
02 PRSNT FIT h, U M "SRT hl,lu '

IftO LET x-x+<INKEY*""k" )*(*«t >
<; INKEY»-"J* .>*tx-u

no let M=w+"irsKEY*--M->*c*tai>

11 a IF RTTR t*,x>™5@ THEN LET h
it*3S LET w*« LET »4b< UO TO 5
33

IIS IF RTTR <y,H)OM THEN LET
K"#. LET w ^b

l£g PRINT HIT w,x, "e"

123 IF x<* THEN PRINT RT b,*j"
"/AT *-w; ri ^l BEEP .03,23 PRINT

RT H,Xi*j? BEER .OS, 10

12:5 IF K^i THEN PRINT RT b,*j"
">RT »,xj"fc"< BEEP .83,23 PRINT

RT B.xj'f' SEEP .63- 10

130 IF t{>» THEN PRINT RT b,*j"

M ;RT a^x;^"' BEEP ,05,23 PRIN
T RT »,xi"_*"' BEEP .03,10

1^3 LET 4*x LET b-¥

14C LET ji*-INKEY* IF *•-"«" Oft

**.-"*'> or **■"*■' OR ■•""•«■ THEN

GO TO 130

143 00 SUB 400

145 00 TO 1Q0

130 IF i*-"A" THEN LU TO 200

iiffl IF «#— S a THLN UJ TO &■

ice rr 4«"**#" then co to 300

1G3 IF a*'-";" THEN tfJ TO 3*0

170 L^T **»"
1399 REM shoot

(j£i TO His©

SINCLAIR USER Annual 1984

99

y&y bZJEP ,©1,-5. r^R 1-1. to we

IF ATTR <h,*-i>-^ THEM T-R1NT AT

*#x-jj"-" ME^T i FUR i^l TU x

1 rRINT FIT v,m-i," "• NLKT !■ (.&
TO l&o

,:_T hifc-ilTTC <v,y_-i_.
205 FOR Yi-1 TO i-l PRINT AT w,
K-u>- " NEXT n

LET h1-x-1 ■ LET y I -<j

ate go to 500

£50 BEEP -01 ,-5 FUR 1-1 TQ 31-

x IF flTTR t*UX+t>>SJ£ THEN PRINT

AT B,x+ij"-"' NEKT i FOR i-t T

31-3! PRINT AT *,x+i;" " NEXT

i Cu TO 100

._': LiT i-.it-flTTR <u,k+i ?

KS FOR n-1 TQ i-l PRINT RT if,
te*n;» "' NEMT r>

25tf LET *f-y< LET Kl**»-1
^JiCe GC TQ 100

300 BEEP ,01,-5 FOR i*l TU »-t
IF ATTR t«-i,y>-56 THEN PRINT
AT »■!,)(;"!"■ NEXT l FOR i-l TU

w-t< PRINT HTj-i,.>," "■ NEMT i
• LO TO 100

LET hit-RTTR <*-i,x>

JOS PUR .-."1 TO i-l PRINT AT w-
n,» " " ! EXT ri

JO* LZT yl-y-i LET k1»x
C£l TO 500

300 SEEP ,01,-5 FOR iwl TO Si-
ll IF ATTR <y + i,*}*56 THEN PRJNT

FIT W+1„X;T NEXT i FUR i-l T
21-v PRINT AT »+j«xj" "• NEXT

1 00 TQ 10Q

353 LET hit-RTTR C*+i,yj

3S5 PCJR n«l TO i-l ' PRINT RT w+
*#»u" " NEXT n

3S8 LET ^1-w+i LET xl-x

ace co to 5©e

39$ REX pjcmj.rv

436 LET h-M-<h<w J+INT < RND»2 >-<
h>*WNT <RND*2> IF h>21 THEN L

ET hHrt
433 IF h<l THEN LET h-hi
435 IF ATTR ( h, 1 )< >b£ THEN LET

H-hi
440'LET l*l*C Kx>+INT CRND*2)-t

l>x>-INT <RNMf2>' IF t>31 THEN L

ET i-u

445 IF ATTR th, I X>56 THEN LET
l-li

456 IF h-M RHD 1-x THEN GO TO 1
000

4Cb RETURN

4$$ REX *Kf>losiQn

500 PRINT AT vtiHlj OVER u " < ia
PV' 6ECP .2,-20 PRINT OVER IjA
TvttXli •■ i.-3l >" DEEP . 1 , JfO ■ PRIM
T OVER 1j.1T *l,xt<"C9g>*' ■ BEEP .
1,4 PRINT OVER 1 ; ftT~JT", *1 i H < i?7
>" BEEP ,1,45 PRINT AT wl/inT"
CfljV 1 SEEP ,1,15- PRINT AT m!,x

"" 50'-. IF l-,it-57 THEN LET $c»«sci-+
20 GO TQ GO
31G LET ^tr-icr+i
511 LET t3tto-tf?U+l IT t9fc«>l9

the:n go to io

5^0 FljR m»l TO 4

522 LET t* -RNt'*2Q+l ■ LET tx"RND
till IF ftTTR <t«,tM?-60 THEN GO
TO 5S2

51-4 PRINT PT tw,t*j INK 2j"j".
NEXT n —

FLASH 1; '^ BEEP £,-25 PajNT A
,^T h, I j FLASH 0, INK 8;" "
1010 L1,'T nan'MAn— 1

iG2._- print rt a,aj "i5«i«p j'jat

,<$*'<,& 1 TO i*utn+2?

Ifl25 tF hit-5Q AHO mif,^ THEN LE

t hit'iae lcj to so

1020 IF n*nX] THEN 00 TO 00

^eoo r?En end ^r 94m*

202G FOR !-» 10 TO 20- FOR n-5 TQ

i B6ET ,02, n NEXT n NEXT i

2021 IF icr^fcr THEN LET h»cr-»

Cr

£930 CL5 PRINT PT 10,6; FLft&H

lJ "** CAXE OVER **"

204G PJ^INT AT 0,21, "»cefr-*- w i«r;

AT 0,Q; M hiGh icort"" jh»ct-

20C0 PRINT RT 21,2, PAPER £j"PRE

ES ANV KEV TO PLn**- At^AIN"

ZB7Q P;TOS£ D

20C0 LL^ GO TQ 4

M£0 RESTORE 9B70- FUR n-l TO lfl
*"903G REPO P*

3040 FDR n-0 TU 7

9IW0 READ i POKE USft P»+n,*
n NEXT m CO TQ 1
"a", 24, 24,0,^0, 10,24,3

530 IF htt-50 THEN PRINT AT v,x

* OVER L^iiP)"' BEEP , 2,-20 P

HINT OVER TTnT" m.Xi "(fllV 1 BEEF-

.1,30 PRINT CfVER l,RfT,«/'(fl2 3

" DEEP .1.4 PRINT OVER 1,AT *,

>CJ" <1Q7> - BEEP ,i,43' PRINT AT

IP.xr^Si" BEEP -i.lS. -EBIKT AT

tit xi" * BEEP .4,-15- 00 TO 101

420 PRINT INK I; AT h,l;"h"jAT h. |

i, IiJ INK 9. " " •

422 BEEP .01,0

9BC0 NEXT

907Q t-ATA

*,32

9800 OATR

■

905Q DATA

91 BO DATA

100-4

91 IE DATA "*■

16,16

9120 OAT A T*

4

9120 OflTR "O- 1

i£

914B Ii.'lin "h"

425 LET hi»*v

LET ti-1

540 GO TQ JO

99* REM sofabU flobbl*

1000 PRINT AT M, It,

;AT h,\>

12£, 90,219

9152 OlTp ■

0,9C,24

91 £0 DnTTi '

,1£,16

L,", 24, 24, 0,24,44,0,0,

c' 1 ,e,B,8,2B,42,e,2B,2

d", 24,24, 1£, €0,60,24,

ff",2*,24, 16,24,52, l£,

0,0,0,20,40,24,20.

e,e,B,£0, 10, 12,20,

24,12£, 153.25S, SO,

l"S,a4,4l, 170,93, 17

lC,40,B4,5G,B4.l7a

Y

'OU ARE the ravenous road-eat-
ing crocodile at the bottom of
the screen. Press T' to fire a
venom blast which will gulp down one
of those tasty toads passing overhead .
The Society for the Protection of
Toads, which objects to the wholesale

slaughter, has erected a forcefield.
Firing while a toad is behind it will
result in all the frogs escaping, thus
ending the game.

Tasty Toads was written for the IK
ZX-8J by Andrew Brewster of Roches-
ter, Kent.

1 REM -'T"

2 LET C-0

3 LET fl-0

4 RANE>

3 FOR R-l TO 5
6 CLS

10 LET M-1B

20 LET F-2*C INT <RND*9>>

30 FOR 8*0 TO 2B

35 PRINT AT 6, 0, "******#WFORC
E* F I ELD*###*#* #****"

40 PRJNT AT 19, 15, "t 1 . e£ i . >■•
,flT IS, 14j "<9si'3*»|>.flt >",RT F,Bj
"<i. 'Qfi-i, J"jAT F+l,Bi"(Bt l-9si

50 IF n<F THEN LET MMS

ea if inkev*-"P" or mma then

PRTNT AT M, 16j".»

65 IF B-J5 AND (1-F THEN GOTO 1
30

?P IF INKEYS-'-p 1 ' OR M<10 THEN
GOSOB 120

00 PRINT AT F,BJ " "

90 NEXT B
10Q NEXT A

120 PRINT RT M, 16;" ■
125 LET M-M^2
130 RETURN

150 PRINT RT M^B, " 9ul& " j AT M+
1,Bj" "
160 PAUSE 30
170 NEXT A

100

SINCLAIR I'SER Annual SUM

V

PENTALPHA

PhNTx\LPHA is a version of an
ancient Egyptian solitaire game
which L Gabb of Nonhficld, Bir-
mingham has converted for use on the
16K ZX-SI. The aim is to enter the
nine counters on the 10 points of a
pentagram. A piece may be entered on
anv unoccupied point and must then be
moved two points in a straight line to
another unoccupied point.

The intervening point may be occu-
pied or unoccupied. If no more moves
aTe possible before all the counters have
been placed, the game is lost. Moves
should be entered by pressing the letter
corresponding to the point where you
wish to enter your counter, followed by
the letter corresponding to the point to
which you wish to move it.

10 LiIM FX1Q>

20 LET J*-" H-EHBfJFftE.lt "

100 PRINT FIT 0,Q; "*p#nt*lPha*" *
TAB 15.. "*">TFIB 14;". , " iTHB 13j"

RB £ t "b, . ,c. . .d.

■ ■
■ ■

,0"

130 PRINT TAB 9i". ,

140 PRINT TAB 19; "F.

150 PRINT THB 9>".

160 PRINT TAB 0^".

170 PRINT TflB ? f '\

m

100 PRINT TfflB 6;"i.";Tffi 23j".j

190 PRINT

200 PRINT TfiB 6t"m&** *ntmr p»v
* to -

500 FOR (1-1 TO 9

505 FDR I-E TO LEN J*-l

510 if not mcate j*<n-37) cm

< PC CODE Jtt. I-i >-37 > RND K CODE

JKI + 1 >-37 > i i THEM LOT0 590
5£0 NEXT I

530 PRINT AT 12-H1,Bj"Y0U CflNNCJT
MOVE fTNfJ HAVE FOILED"
540 GOTO 510
600 LET fl*-" M

eie let e*-" M

£20 PRINT RT 12+PL11)"

630 PRINT AT l£+H,7>rijTfle ISj'T

£4iS LET fl»-INK£Y*

650 IF RtK'-fl" QR RtV'jr THEN GO
TO 640

666 PRINT RT 12+P1, l3;fl»

670 IF P<LUt'E fl*-37> THEN GOTO
1001

660 GCJSUfi 1500

605 LET fMA

606 LET B-Y

690 PRINT RT R,B*"U"

720 PRINT RT l£+M,20>"?"

730 LET B»-INKEY»

740 IF Ef»<"fl" OR B*VJ" THEN C£
TO 730

750 PRINT RT 12+M,£0;B*

7S0 IF PtttX'E 0*-y7 3 THEN GOTO
1051

77Q FOR I"£ TO 11

760 IF Rt«J* I > nUt' 0*< >J« 1-1 J

t=jHf B*<>J*tI+l> THEM L03UB 1000

730 NEXT I

795 LET PC LODE B«-37)-l

000 C.QSUB 1530

010 PRINT RT R,B;LHR» < LODE R*+
ISOjAT X,Yi "0™

820 NEXT Pi

900 PRINT RT li0j" >UELL WJNE< H

j*lO PRIRT RT 0-13;"Pr**s* r to r
UTi";Tt"(E" la;"ar £ to fttcP "

920 LET 0»-INKEY*

9^0 IF fl**"R" THEN RUN

940 IF B*""'i" THEM STOP

930 OCJTO 920

1000 LET P<C,UOE FW-37>-6

1001 PRINT AT li+n, 11 ; "INVALID H
OVE" ,*T A,Ei;LHR* < LODE R»+120J R
MO B*0""

JUOJ! FOR 1-1 TO 50

1005 NEXT I

1010 fJOTG 565

1500 I* B*»"" THEM LET T«-fl«

1510 IF B9<>"«

1520 IF T*-"R"

1530 IF T*>"R"

ET X*3

1540 IF T*-"F"

T K*9

15^0 IF T*-"H"

15£0 IF T*«"I"

T X*9

1570 IF T*-"fl"

T YM5

1500 IF T«'"0" OR T**T'

THEN LET T0-0f

THEN LET X-B

RND T*<"F M THEN L

CM T»-"G" THEN LE

THEN LET X-7

OR T*-"J" THEN LE

CM T*- J, H" THEN LE

T V-6

1590 IF T«-"C"

160-0 IF T*-"V

1610 IF T**"E M

T Y-£4

L62fl JF T^-F"

L630 IF T*»"C"

1640 RETIJPM

THEN LE

THEN LET Y-12
THEN LET Y-10

OR T*-"J" THEN LE

THEN LET
THEN LET

t-10
Y-20

H

i Ml' USER .Umual im

101

^-^^-^-i-l-l-lT

- r
111

»**■ " T "■

■ ■ r ■
• 1 ■ « ■

I ■ ■

i **#*■ '■ •
■ ■ » « ii-ii ■■

+ "■■ !*■"»'"■ " ». ." *■"■"-

■ *#■■■ ■ - j j m

»*■■•*■ * « fe a a

■ ■ ■

YOUR QUEST begins as you find
yourself in the dark on the first
floor of a fifteen-level tower.
Your ultimate goal is to climb the tower
and find the Great Jewel of Light. On
the way you must find keys, armour and
many other objects which are essential
to your progress.

Opposition is in the form of weird
and wonderful creatures which appear
from the gloom and which must be
destroyed. With luck you will climb the
tower, find the jewel and find the ring
which tells you how to leave (he tower.
You may even be helped by the Great
Wizard.

Enter *'1NF0'* to obtain a complete
vocabulary list, including the code
numbers of certain vital objects, Com-
mands should be entered when
'NEXT?" is displayed. To u&e an ob-
ject, enter its code number.

The program was written for the 16K
ZX-81 by Colin Hunniford of Berk-
hamsted, Herts, and is the first adven
ture game to be published in Sinclair
Uier. We hope that, as well as providing
enjoyment, it will also provide hints and
inspiration for those interested in writ-
ing adventure games.

- -

- ■

- -

1 REM MMMIWMMMMMMMMMMMMr-FMrinr-l.M
tfMMMMMMMMl 46 ch.araefc#r*rinril"|l"IMMMM
M M MUMMMMMMM MMMMMnrirrn MMMMttllttMMMMH 1
MMMMMMMMMMMMMMMMMMMMMMMMHMMMMMMM
tl MMMMMMMnflMMMMMMKMMMMHnMriM M

2 LET fl*-"2RBC401 1B6021?0620T"
EC6B07723 1 0F92R0C43 1121001 SED3B0
C4001DE02EDB0"

3 LET A*»R*+ ,l 2l2f032235)402RGC
40 1 1 B602 1 9220E 4 0C 3 "

4 LET R»-A»+"2A0C40e615C30620
237EC6007710F923C1 10F2C9"

3 LET A*-R"+"2A0C400613C30e20
2336S0 J OFB23C 1 1 0F4C9 "

6 LET R»-fl*+^2R0C40Il0E0BI33e
00233634 1 120001 93603233636233603
1 120001 93680 1 1 2000 1 93606232 336BS

m

7 LET A*-AR+ "2R0C40110E001936
96 1 1 2 100 1 93600C3D940"

B LET C- 1631 3
9 FAST

10 FOR 1-1 TO LEW A* STEP 2

11 LET C-C+I

12 POKE C16*<CGOf R«<I>-2G5+C

DOE R«<i*i:-2e

14 NEKT I

dim R^cis.e.ej

SLOW
PR WD

LET D«-CHR«
DIM E< 145
LET E« 1 >-9999
LET C-16314
LET T-B
GOTO 130

13
16
20
23

30
40
50
SB
00
90
100
110

LET r-iwt ?rnd*£)+i

LET 0-INT CRND*6>+1
IF A«( N , A , B >OCHP» THEM G
0T0 90

120 RETURN

130 IF LISP 163930USP THEM PR
TNT "WELCOME TO ' " j TAB USP Cj"MIJ
RKY ADVENTURE 2'PHOENIM TOWER" J T
AB USR CjTRB UER Cj"YOU RPE RBOU
T TO ENTER THE TOWER" ;TRS USR C
"IN WHICH YOU MUST FIND fl KEY,"*
TRB USR C*"A JEWEL, A TORCH RNO M
RNY OTHER 1- 'TRB USR C> "THINGS Tn
SUfiV I VE . '■ > TRB USP C 'LJOULD YOU L
IKE 1NSTUCTI0NS*"«

140 INPUT B»

130 PR TNT " "jBBiTRB USP CiTRB
USR Cj

160 IF B0-" " THEH GOTO 130

170 TF B»C1>-"Y" THEN GOSUB 189

IBB GOTO 220

IBS PRINT "YOUP TRSK IS TO GET
THE GREAT" ,i TRB USR d " JEWEL FROM

THE PHOENIX THAT "i TAB USR C> "LI
VES OH THE 13TH FLOOR" I TRB USR C
j "UHEH rttr.t ! I? DTSPLRYEO. ENT
ER"iTRB USP C'THE WORD DR Nf.'MBE
R YOU WANT TO " i TRB USR Cj H U8C.Y
OU WILL LERRN THE RULES OF". TRB
USR Ci-'THE GAME A? VOU ;PLRY. " : TR
B USR C P " 9ood I ucf* "

190 PRINT TAB USR C ■ TAB USR C ; "
WORDS ■ MOVE, HELP , BASH, UP DOWN . " i T
RB USR C: "TAKE. DROP. INFO SAVE. S.N
eE2£.";TAB USR CjTAR USP Ci"l"ST
RENGH" "2-TRERSUPE"

IW PRINT TRB US* Cj "3- JEWEL" ■ ■
4-SPFLL BOOK".: TRR USR C ■ "^-ifEY",
"e-SWOPD" ;TRB USR Cj w 7«R TNG" . "S*
LIGHT"; TAB MSP C: "?-SH tELD 1 " . "IB*
URTER M J TAB LISP C ■ " 1 1 -WANP" Tfl3 M

SP Cj ,h 13-RPrirjup" . " i4-n_u&" i trp i
sp CjTAB usp c
196 ppiht "press r k'ey and writ

,-nn
210
?13

240

230
?60
2^0
290

ir ikhf'---'*-"" tmeh cfim 299

RETURN

RFM Jr-rc th' 4 '\r.w\* i r t -™t

THST

FHP N-1 Tf> 1^

FOR t=2 TO S

COSUB 90

LET A*.'N,R.e > -"«'"

GOSUF' 'in

LET flrn.(i,E!'i- l, G"

I "J

SINCLAIR USER Attmol im

300 NEXT T 90* IF PN0>„6 THEN GOTO 1620

3l« GOSUB *0 919 GOTO £71?

- !4 n TF N-M THEN I FT ftKN,B»BK 911 P.EM m^**

H p$ g 915 IF T~>0 THEN GOTO 1153

350 IF N-2 THEN LET A*'N.fl.B*-C 920 PRINT "WHICH WAV? <N,E,W.-3>

HP* 14 '"J

36G IF N-3 THEM LET fl*< N . P . R * 930 INPUT E*

HP* "lJ 935 PPINT 6*

370 IF N*£ THEN LET H«<N,R.B?-C Q40 j F P.*-"" THEN Gnyn 4g06

HP* 13 950 LET ft*fl*< &*< 1 >="?" >-< D*< 1 >■

?ee jp M-7 THEN LET R*<N,R,B>*C "n"*,

HP* 10 9G0 FOP I»9 TO 14

390 IF N-8 THEN LET |WK,flJK gfyg LET £{ 1 >*E< 1 >-€< I 1

HP* 9 9#0 NEXT T

400 IF N-9 THEN LET fl*< N , R j B >^C 993 LET R"B+f B*': 1 >«"E" >-< B*< 1 )™

MP* £ "ir\

410 IF N»10 THEN LET R*(N,R,B>- f ncin ir rnvt THEN mm 14443

CHP* 7 1P06 IF R>£ nr fK1 OP B"-', np ' 1

420 IF N-il THE" LET R*<N,fl,6>- T HFN GOTO 11 10

CHP* 6 IOOQ LFT M-R*M. . R >

430 IF N-13 THEN LET fWN.R'B)" 5010 IF D*-"' ■"' THFH GOTO 11 10

THP* 4 10?B IF Yl'-R AND Y2-B THEH GHTrt

450 IF N-M3 THEN LET fl*< N R,B> | ?0 p

CHP* 3 1030 LET Yl-fl

460 GOSUB 90 1040 LET Y£»B

470 IF N-13. THEN LET R*CN ; R.B>- \t^.U IF f.*-CHR* 10 THEN GOTO 10]

rwPi IB

490 GOSUB 90 J0K0 if D*>-r:HP* 1* THFH GOTO M '

490 LET A*'N,R,BV""S"

500 FOP 1-1 TO 5 1063 IF Dl-CWP* 17 THEN GOTO 176

510 GOSU0 90

^0 LET fi*<N,A,B WTHP* 17 10 ?e GOSUB 3220

350 GOSUB 90 10<30 IF D*-CHP* 3 OB D*-CHR* IS

560 LET R*VH J R,B^-CHP* 15 TWEN LET t-1

570 NEKT I H00 COTO £70

590 NEXT w 1110 IF USP C+USP 1 6593< >USR C T

■spO LET N-l HEN PPINT "BONK. YOU HRVE HIT R U

600 LET L-l RLL"jTRB USP G

610 GOSUB Q & till LET R-Yl

615 LET Yl-fl ux2 LET B-Y2

620 LET Y2-8 U£0 GOTO 913

630 SLOW Jt 23 REM l*Ofl*t*r*

£40 FOP I"»0 TO 5 1130 LET X-IMT (8ND*7)S0+]

£50 NEXT I U40 PPINT TAB HSR Cj"MEPE TS A"

.-_- rt PPINT TRB USR C;TAB USP C:T , „ UC , LF M EAGLE TPTCOPD MUSHM

m irf- C' H, YOH RPF nM TOP GROUND HH TP oc NUMPir GROn "<M TO

-LOOP OF";TOP USP. '" " T Hr f«W( Tn k+7>jTRB USP Ci

JEP H 1 150 GOTO 1090

fi*3 PPINT TRB inp Ci H YOU ENTFP 1155 PRINT "WHRT RBOUT THE MDNST

IHPOUGH RN OPEN DOOP" 1 TRB USR C 1 F p T "

"THE DOOP ?LRMS SHUT REHTNr. YfN" tlM cnT ,r, €7Pt

TRB USR C 1?0O PPIHT TAB LISP C ' " PflPPON'?" , 1 T

^66 PFM itiPUrt cNfittt'Iirte ^r ijrp n

670 IF USP C-0 THFN CPTO 4900 t ? 10 nfiTn <st^

673 IF E< 1X200 THEN PPINT "YOU 1215 pp^ s t«iF»

RPF FFFLTNG TlpEO"iTRB USP CJ ^20 IF m THEN GOTO 1155

C80 PPINT "NEWT ? '*.( l22 ^ IF R*< 1 ,fl,BWV^" THEN GOTO

690 INPUT B* !33d

700 PPINT B* T riR USR C: i^-^n IF Ei"i^"'t THFH GOTO 1330

70S IF 0*^-"" THEN GOTO 600 ^^ jp l-^ THrH ,- nTn 44^^

710 IF W<1>- ,, H"' THEN GOTO 913 .^ 4rt LFT , H +1

720 IF B^i)-"'^ THEN GOTO 1B40 .^ PPTMT -./nil HRVE GONE 1 IP THE

73B IF B«13- ,, U" THEN GOTO 1220 gtEpg-

730 IF B*C1^"B" THEN GOTO 1490 |g ^ ^ CTa ce5

734 LET B*-B»+" " t^Tfl IF T^0 THEN GOTO 1133
733 IF 9*< TO 2 5- "DO" THEN GOTO

1270 .■ . ,..•:■.. X*'*' .-.■.'

7*0 IF BKD-'T 1 THEN GOTO 1660 ■* ,W m *l'*y '. .%* v

750 IF B*< TO S>-"DP" THEN GOTO ,vX\.>V>* •.■*'" . S.\

753 IF B*-"SR^E " THEN GOTO 443 ,v» *" " ,■.**.■"*'"..

760 IP B•<l>- ,l ^■ THEN GOTO 2100 .% *' v .'vft-A^ "

770 if b*c to 2?-"sn" thew goto •'•*5;¥a*"" j< " *" '

3 bo . ,*;■*-.*■* ■* *'■",■*

790 fpp 1-1 to 14 .-.-:■;•;■■■■

790 IF 8TM I+CHPt 0-B» THEN GO , <->:■* >" y

to 030 •:■■*■

9P0 NEXT I
SIB GOSUB 190

020 GOTO 670 . .■
830 IF fCVJBL B*-?>0 THEN GOTO Vfl
L 0**100+3800
040 PPINT "SOPPV, CANNOT DO THRT

030 GOTO 670

860 If T>0 THEN GOTO 1153
805 PRINT "YOU HRVE JUST SNEEZE .;.*,.;
D"
090 LET E< 1 >-E< 1 >-l

4 h

■ h ■ -

SINCLAIR USER -4™W ;«W^

103

i 273 IP p*f |_ . A . B v ^ "«; ■■ thfn GOTO
(398

1280 IF FC5X1 THEM GOTO 1330

1290 LET L-L-l

1308 PPTNT "YOU HAVE WNE DOWN T

HE STEPS"

131* TF L-^0 THEN GOTO 137fl

1320 GOTO 665

1330 PRINT "NO STAIRS HERE"

1340 GOTO 670

1330 PRINT "YOU NEED R KEY"

1368 GOTO 670

1363 REM esc*P#d

1370 PRINT TRB USR CjTAB USP C "

UELOOME m jTRB USR Ci<"YOU GOT THE
JEWEL AND ■' AND EC 3 »8 > ] TRB USR
Cj"£"jEC2>j' ! WORTH OF TREASURE
AND VOU'JTRS USR Cj'GOT AWRY WIT
H "' j EC 1 >i M SP»"

1388 PRINT TAB USR C ) TAB USR C;"
WOULD VOU LIKE ANOTHER GAME' "j

1330 INPUT B*

14R0 PRINT B»;TAB USR C;

1410 TF B*-"" THEN GOTO 1380

1420 IF BKn-'-V THEN J?UN

1433 CLS

t430 RAND USP 1SS0T

1433 REM di*d

1-##B PR TNT TAB USP C"WHAT A PTT
v, VOU HAVE DJEE>";TAB USP C;f"BUT

OTJ STTLL GOT TNE lEUEL AND '■ R
ND EO^e^TRB USP Cj "VOU GOT f

teCS>;" WORTH OF TPFHSUPE 1 '

1430 FOR 1-0 TO 9

1468 IF USR 16563 THEN NEHT I

1483 GOTO 13B0

1486 REM fiOht

1490 IF T<1 THEM GOTO 4700

1493 LET MS- 1 NT < RND*2000 >

J 300 LET PI*! NT CRND*MS>

1303 IF E<13»0 THEN LET M-M-INT

<RND*i00>
1310 LET Y-INT <RND*E<i>J
1313 IF E(9J>0 THEN LET Y-Y+INT
CRND*E< 1 >J

1520 LET K-INT <RND*6>*£+1
1330 PRINT Tfli USR Cl "OUCH KICK
KNOCK BRTTERBBSH PUNCH "< X TO

X+3>
1340 LET E<1>-EC1 )-M
1330 IF EM XI THEN GOTO 1440
1360 LET MS-MS-Y
1370 IF WS<1 THEN GOTO 1390
13B0 GOTO 1300

1130 PR TNT TRB USR Cj"'YOU KNOCICF
D THAT MONSTER R MILE"
1600 LET T-0

1603 IF A8C L * A , 8 )-CHR* 13 THEN L
ET RKL,R,B>-CHP0
1610 GOTO 670
1620 PRINT TRB USR Cj" AND DRRWN

ATTENTION TO YOURSELF"
1633 LET T-l
1630 GOTO 1130
1640 REM tik*

1660 IF T>0 THEN GOTO 1133
1670 LET DB»A*<L,R B 1 ^
1673 IF D**CHR> 1? OP 0--"B" OP
D»-CHR1 OR D*-"S" OP D«-CHP» 1
7 OR Di-CHR8 IS THEN GOTO 1740
1676 PRINT "BK"
1690 IF D»-"G" THEN GOTO 1720
1690 LET EC CODE D« 5 -EC COM D«>*1
1700 LET ft*<L,fl,B>-CHR*
1710 GOTO 678
1720 LET EC 2 5-EC2X-INT <RND*1B08

1730 GOTO 1780

1740 PRINT "NOTHING HERE TO TAKE

H

1730 GOTO 670

1760 PRINT TRB USP C;"¥OU HAVE F
ALLEN INTO MUSH"

1770 LET EC1>-E< iVlNT CPND*100>
17S0 IF EC 1X1 THEN GOTO 1440
17B0 PRINT TRB USR C;"BUT YOU RP
E RLL RIGHT"
1BO0 GOTO S70

1B10 PRINT -HERE IS R WIZARD RND

HE GIVES" j TAB USP Cj"YOU AN OBJ

ET RND HE SRYS ' "

TF

1920 LET

DY11 >+4^

1823 LET

1S30

1933

1836

1940

1930

i960

A»C L,fl.pi>-CHR* < INT ■'PN

0»-A«KL.R,

D*-CHpi 12

B^

THEN

GOTO 18?

1978

1980
LS9Q
2000
2004

2003

P010

GOTO !0?0

REM hi- IP

IF PND>.7 THEN GOTO I9$8

PR TNT "5OPPY.W0 HELP HEPE"

LET ECl>-ECl>-ie

IF £(1K1 THEN GOTO 1440

GOTO 670

GOTO 1820

GOSUB 193

REM drop

IF T>0 THEN

PRINT

GOTO 1440

WHTCH NUMBER WTLL YO
U DROP? "j
2020 INPUT Bt
2023 PRINT 9-jTAB USP Cj
2030 FOR 1-3 TO 14
2840 IF STR» I-B* THEN GOTO 2008
2030 NEXT I
2068 GOSUB 193
2870 GOTO 2818
2080 IF ECVRL BIX] THEN GOTO 43

2083
2098
2093

2100

LET ECVRL

GOTO 670
REM iflf-o
PRINT TRB

B«>-E<VRL B»W

USR C> "YOU HAVE

'jE<2>j" OF TREASUPE" ' TAB USR Dj
1 RND " j EC 1 >j ■' SP« AND YOU ARE O

N"jTAB USR Ci "LEVEL '
2118 GOTO 818

SAVE "PHOENIm"

RUN

PRINT "YOU HAVE

2128
2130
3180

*"

3110

3200

/L

m jEC1>j" SP

GOTO 670

PRINT "YOU HRVE £"iEC2>j" 1
F GOLD"
3210 GOTO 670
3215 REM object*

3220 PRINT TAB USP Cj "HERE IS fl"
'TRB USP CjC-PIT OF MUSH" AND D8
-CHR" I7>K"MI9E UJZAPD" AND D»-
3228 PRINT TAB USR Ci "HERE T* H"
iTRB USR CjC'PIT OF MUSH" AND O*
-CHP* 17?iC"WISE WI?ARD" RND 0*-
CNR« 19 5; < 'SOLID WRLL" AND €>**"*
">^"SrLVER SWORD" RND r-a-CHP* 6
>t< m SOU> PING" AND M-CHP* 7>jC"
TORCH" RND D*-CMR* 8?iC"P0SH SHT
ELD" RND f*-CHP* =i v ■'" BUCKET OF
WATER" AND DS-CHP* 10^ i C "SILVEP
WRND M AND D»-CHR* lt>K"SUIT OF
HEAVY ARMOUR" AND M-CHR* 13>iC"
WOODEN CLUB' 1 AND D*~CNPi f4>;i" lc ;
TAIP CASE" AND D*-'"S" ■>.' "GPRND P
HOEHIH GUARDING A JEWEL" AND D**

i"HP* 3>jC"MRSTY
AND D*-CHP* \ w ,
SURE" RND D*-"G
I 9* AND 0*-CHR*
THING" AND D»^rnP*
EY" AND D*-CHP* 55
3230 RETURN
3248 REM Ti^ht
3380 PRINT TAB USR
LIGHT? I IP"; TAP USR
3303 PRINT TAR I r.r-

r

LET r>«-0"'L . A-.' A

GOSUB 3220

PRINT TAB i|pp r, »q

r

I FT D**ftf I

r,nn in i^r'rt

FPU IT TRfl

I OOKING MONSTER"

'' "HOARD OF TppH
5 < "BOOK OR '3PEL
4 : C " LORD OF NO

0> | '"GOLDEN Y

TAB USR

C

C "NORTH" TAP

1

1 I TRB

0+^0^6 \.Bi

1 I Cl "FAST" :TAP

C "WEST"* TRB

USR
3310

ir^p

'i inn
3^53
USR C

3340 LET r*-Atn .n.B+^R^^^
3343 GOSUB 3220
338B PRINT TAB )i^p
lr=:p c

3333 LET D*-R§< U , R , B-< QM > )
3368 GOSUB 3220
3363 GOSUB %9G
3370 GOTO 670
3400 IF T>0 THEN GOTO 1135
3403 PRINT TRB USR C "THE SPELL
BOOK MAKES SOMETHING" : TAB USR Tj
" FOR YOU"
3410
>

3428
3380
3600
3610

LET EC 1 >-EC 1 J-INT <RND*E< I f

GOTO 1020

GOTO 3188

IF T<1 THEN GOTO

PRINT TAB USP Ci '

4700

YOUR SWORD

KILLED THE MONSTER'
3620 GOTO 1608
3700 PRINT TRB USR Cl"TO GET OUT

OF THE TOWER -YOU MUST" j TRB USP
Cl-GO DOWN THE STEPS ON THE BOTT
OM-jTRB USP Cj "FLOOR"
3710 GOTO 670
3888 PRINT TRB USR Cj "YOU SWITCH

ON THE LIGHT AND SEE'"
3810 GOTO 3383
3988 GOTO 3188
4000 IF A»C L , R > B J-CHP* 3 AND T>0

THEN GOTO 4028
4810 GOTO 3100

4020 PRINT TRB USR C i "WATER HRS
PUT OUT THE PHOENIH"
403O GOTO 1600

4100 PRINT TAB USR Cj-'UITH A WAV
E OF YOUR WAND, YOU ARE"; TAB USP
Cj' h DN THE NEHT LEVEL"
4110 IF L<13 THEN LET L-L+l
4120 GOTO 1600
4300 GOTO 3100
4400 IF TO THEN GOTO 4?00
4403 PRINT TAB U5P CWOU SURE 8
ASHED THAT MONSTER"

4410
4430

UP

4448

4443

4430

INT

SS'-jTRB

Y. "j TAB

GOTO 1600
PR TNT "THESE

STEPS DO NOT G

GOTO 670

REM M<« a*v*

IF USR 163S30USR C THEN PP

TRRT TARE RECORDER RND PRE

USR Cj"NEWLINE WHEN RERD

USR CjTRB USP C;"r*n lo«

C;

TO DROP"

d 1 x k I " j TAB USP

4460 INPUT B*

4470 SRVE "Hh"

4480 GOTO 678

4300 PRINT "NOTHING

4310 GOTO 670

4608 PRINT TRB USP Cj

4618 GOTO ?20

4780 PRINT "NOTHING HERE TO BRSH

n

4710 GOTO 670

4880 REM aer*oll off last <,<^rds

4988 PRINT TAB USR C;

30O0 IF PEEK CPEEK 163 < 36+P£EI' 16

397*236+1 XM2B THEN GOTO A "00

3010 GOTO 673

5108 PRINT "YES, YOU HAVE fT*

31 10 GOTO 670

104

SINC1JUR USER Axmtat W4

Helpline

Our resident expert, Andrew Hewson, has

again been busy answering queries. In this

section he has collected all his advice on

particular subjects to give you the best help

in making the ownership of a Sinclair

machine more fulfilling.

984

SINCLAIR USER Annuti! I<t84

105

PEEK, POKE

are explained

mm

EVERY MONTH a selection of
queries from reader s on (he
difficulties they experience are
answered in Sinclair User. Here is a
selection of those which offer advice
which will be of universal interest.

David Anthes of Bridgport writes:
My ZX-81 has a bug. When I POKE
57 into various addresses as per
page 163 of the manual, I get weird
effects. Sometimes the machine
crashes but Sinclair claims there is
nothing wrong with it.

When you enter PRINT PEEK ad-
dress* your computer PRINTs a posi-
tive integer number between and 255
inclusive. That is the number which
your machine holds in the byte at loca-
tion "address". The value of "address"
must be a positive integer between
and 32767 on the 16K ZX-81 or Spec-
trum.

POKE is the complementary com-
mand to PEEK. It puts a number into a
location. The form of the command is;

POKE address, number

Where address is a positive integer in
the range to 32767 — 16K machines
— and number is a positive integer in

• Please address problems and quenes to Andrew
Heuwn, Helpline, Graham Close, Htewbury,

Oxfordshire.

the range to 255 it is a dangerous
command because POKEing the wrong
location can cause the machine to crash
for any one of a hundred reasons.
PHEKing ta i menu of looking gt what
your computer is doing, whereas PO-
KEing is a way of putting a spanner in
the w T orks; if you put the spanner in the
wrong place or the wrong spanner in

the right place you can cause havoc.
John Hawes of Glamorgan wants tn
PEEK the ZX-81 display file. He asks:
Is it possible to discover whether a
given character is at a given posi»
tion in the display of the 16K ZX-
81?

There are two golden rules to remem-
ber when manipulating the ZX-81 dis-
play. They are:

The ZX-81 display file must always
contain at least 25 bytes filled with the
NEWLINE character, decimal 118.

The IK ZX-81 display file contains
only the characters which have been
PRINTed or PLOTted, plus sufficient
spaces to fill any gap between the left-
hand side of the screen and the charac-
ter in question. The 16K ZX-81 display
file contains 25 lines of 32 characters
unless SCROLL has been used since
the last CLS. The following routine
PRINTs the character at row R, col-
umn C of the 16K ZX-81 display file;
10 FOR 1 = to 5
20 PRINT "ABCDEFGHIJKI M

NOFQRSTUVWXYZ ;
30 NEXT 1
100 LET D = PEEK 16396 + 256*

PEEK 16397
110 INPUT R
120 INPUT C

130 PRINT AT 21,0; CHRS PEEK
(D + 33*R + C)

Peter Bankes of Debenham asks: Is it
possible to poke the Spectrum to
get caps lock?

The caps lock condition is stored in
bit 4 of FLAGS2 at address 23658 in
the system variables area. When bit 4 is
set, all entries will appear in capitals.
Hence a program can determine
whether caps lock is set by checking the
status of that bit and altering it if
required.

The condition of bit 4 may be
checked from Bask in a somewhat cum-
bersome fashion as illustrated by:
10 IF INTfPEEK 23658/8)= 2MM
(INT(PEEK 23658/8)/2) THEN
PRrNT "CAPS LOCK NOT SET":
GOTO 30
20 PRINT "CAPS LOCK SET"
30 STOP

To set bit 4 from Basic and hence
turn on the caps lock enter

POKE 23658, PEEK 23658 + S
To turn if off again, enter
POKE 23658, PEEK 23658 8

Alternatively you may wish to use the
ROM routine which "toggles" the caps
lock. The routine is located at address
4317 (I ODD hexadecimal) and succes-
sive calls of the form
RAND USR 4317
turn the caps lock on and off.

J

106

SJMCLAIR USER Annual IWtt

5

Machine
speak

MANY PEOPLE have had
problems with machine code.
Ljohn Stevens of Hammer-
smith, London writes: I am trying to
learn how to write machine code
programs but I am finding it diffi-
cult to understand the meaning of
some of the words, which are used.
Can you explain as fully as possible
what is the difference between a bit
and a byte, and between a register
and a variable?

A bit is the fundamental building
block of computer memory and can
exist in only one of two states. The two
states ean be thought of as representing
ON or OFF; TRUE or FALSE; YES or
NO; UP or DOWN; MALE or FE-
MALE or any other pair of logically
opposite conditions. The mechanism by
which a computer memory works is not
really important to us but in the Sinclair
computers the state of a bit is memor-
ised by setting a microscopic solid state
switch either ON or OFF as appropri-
ate.

The usual notation is to think of one
state as the ZERO state and the other as
the ONE state. A bit is considered to he
set when it is in the state representing
ONE and to be re-set otherwise. That
notation allows us to speak of a given
pattern of bits in terms of its binary
equivalent and by converting the binary
number to a decimal each bit pattern
can be given an exceptional positive
integer number.

For example, consider eight bits of
which the right -most four are set and
the left -most four are re-set as illustrat-
ed in table one. The binary pattern of
the eight bits can be converted to a
decimal if it is remembered that, in a
binary number, the right -most column
is the units column; the next column to
the left again is the fours column and so
on, doubling at each move to the left.
The decimal equivalent of 00001 1 1 1 is
therefore:

0*128 + 0*64 + 0*32 + 0*16 +
1*8+1*4+ 1*2+ 1*1 = 15
Obviously it is inconvenient to refer to
bits as the right -most or the third from
the right and so the convention is adopt-
ed of numbering the bits from the right,
starting at zero as shown in table one.

When that convention is used the num-
ber of each bit is also the power to
which 2 must be raised to give the value
of the column. That is:

2 bit number = column value
Bit 3, for example, is in the eights
column because 2' = 8.

I chose to consider a group oT eight
bits together because of the Z-80A mi-
croprocessor at the heart of the Sinclair
computers is designed to operate on
eights bits at a time. The term 'operate'
covers all the types of task which the Z-
80 A can perform directly, such as addi-
tion, subtraction, rotation, logical

AND, and the like. Thus although a bit
is the fundamental unit of computer
memory* bits are usually manipulated
together in groups of eight, so a group
of eight bits is called a byte — pro-
nounced bite.

There are 256 ways of arranging the
contents of a group of eight bits. The
first is 00000000, the second is
00000001, the third is 00000010. Thus
each of the bytes in RAM can be used to
hold a single positive whole number
lying between and 255 inclusive by
setting or re-setting the eight bits in the
byte according to the binary equivalent
of the number.

The Z-S0A does not alter the con-
tents of memory directly when u is

executing a program; rather it copies
the contents of a location in memory
into one of several special locations in
the microprocessor called a register and
then operates on the contents of the
register. The Z-80A is a powerful mi-
croprocessor because it has many regis-
ters and so it can hold several numbers
at once, thereby reducing the need to
make time-consuming transfers between
the processor and memory.

Most of the registers have one or
more special features. The most import-
ant one is the 'a' register or accumula-
tor, so-called because the results of most
arithmetic or logical instructions are
accumulated in the 'a' register Some
instructions use a second register as a
second source of data together with the
'a* register.

For example the instruction;
add a,b
means add the contents of the V regis-
ter to the contents of the *b' register and
leave the result in *a\

Thus a register is a dedicated location
in the microprocessor which has
specific attributes and functions, A vari-
able is a location or group of locations in
RAM which are used by a particular
program. If the program is written in
Basic or another high-level language,
the variable is given a name and all
references to the variable are made
using the name.

The next question, from Alan Ber-
mingham of London , follows from the
previous one. He asks:

What do the following programs
do — an assembler, a disas-
sembler, an interpreter, a compil-
er?

A machine code routine consists of a
sequence of instructions which the Z-
80A understands directly with no need
for prior interpretation. The simpler

Switch

Off

Oil

Off

Off

On

On

On

On

setting

State

Binary

pattern
Bil

number

Re-aet

•

7

Re-set

6

Re-set

5

Re-set

A

Set
1

3

Set
1

2

Set
1

I

Set
1

Table I. Three waya of representing a group of cighi
and the four rlghi-mosl are set. The hit number is

bits of which the four
shuwn on the bottom

left-ntoBl arc re-*ci
tine.

10 FOR 1-232% TO 23)25

2Q INPUT '£%

30 IF Z$ = '*S" THEN STOP

40 PRINT ZS;" "l

SO LET Z$(l)-CHRS<OODE Z$4IW"(<X)DE Z*(l) 57)>

60 LET ZS<2) =■ CH RS{CODE ZS{2)-1 *{CODE Zt(2) 57))

70 POKE U 6 'CODE Z|(l)+CODB Z*(2)-816

SO NEXT I

Table 3- A Spectrum program to load 30 two-character hexadecimal codes into- the printer
buffer.

SINCLAIR t'SfcR Annual IW4

107

instructions are held in one byte of
memory but the more complicated
instructions can occupy as many as four
bytes.

Generally, the instructions are ex-
ecuted in the order in which they are
encountered, although there are excep-
tions. The Z-80A keeps a note of from
where the next instruction is to come by
means of a special register pair called
the program counter. Thus if the loca-
tion pointed to by the program counter
contains the number 128 in decimal —
80 in hexadecimal — the Z-80A will add
the contents of the 'a* register to the
contents of the 'b ! register and leave the
result in the accumulator, because 128
is the decimal machine code instruction
for

add a,b

The decimal or hexadecimal codes

C A disassembler is of

use when analysing

code written by

somebody else'

for all the 600 or so instructions in the
Z-80A instruction set are difficult to
remember and so for that and other
reasons machine code programs are
almost always written using an assem-
bler program. An assembler converts
instructions like add a,b to the correct
code. It also allows the programmer to
name variables, add comments and give
labels to various points in the program
and to call subroutines using the labels.
A good assembler will have other facili-
ties as well, all aimed at making the

programmer's job as straightforward as
possible.

A disassembler performs the opposite
function to an assembler; it converts a
sequence of numbers into a sequence of
mnemonics which are easier to under-
stand than i he original code. A list of
the more important mnemonics is given
in the Sinclair manuals in Appendix A.
A disassembler is of use when analysing
code written by somebody else to dis-
cover how it works.

The output from an assembler is a
program which the microprocessor can
understand directly because it consists
of machine code instructions. In con-
trast, a program written using an inter-
preter, such as Sinclair Basic, is held in
RAM in more or less the form in which
it was entered by the programmer.

Interpreters are high-level languages
which bear little or no relationship to
the instruction set of the processor on
which they are run. Every time the
program is executed;, however., each line
must be analysed by the processor be-
fore the required action can be taken.
The principal disadvantage of the sys-
tem is that the programs can be slow to
executCj because the processor spends
most of its time determining what each
program line means.

A compiler circumvents the problem
by analysing each program line once
only and then storing a sequence of
machine code instructions which are
equivalent to the original program.
Thus the speed of a machine code
program is obtained without losing the
convenience of a high-level language.
The machine code produced by a com-
piler can be somewhat tortuous and
inflexible and so when efficiency is
essential an assembler is used instead.

Hex code

2A 65 SC

44

4D

3E OO

77

7E

FE OO

CO

3EFF

77

7E

FEFF

CO

A 7

23

ED 72

GB

A7

ED 7A

03

Lfl 17

Table 1. A Spec
beginning of the
the stack.

Assembler code

LD HL/23653)

LDB\H

1.1) C>L

[,D A,0

LD (HL),A

LD A^HL)

CP

RETNZ

LD A,255

LD{H1.},A

LD A N (HL>

CF25S

RET N2

AND A

INC HL

SBC HL,SP

RETZ

AND A

ADC HL,5F

fNC BC

JR- 25

Comment

Set HI. in address ofipare space

Copy HL

Eo BC

Set A to

Copy A to memory

Copy memory back u» A

Compare i-lmiIi

Return it error

Set A To 255

Copy A to memory

Copy memory back to A

Compare result

Return if error

Clear carry flag

Incrernenr III,

Subiract slack poimer from HL

Return if finished

CEear carry flag

Add stack pointer to HL

lncremem BC

Repeat Ibr neat memory local ion

trui n machine code program io test each memory location between the
spare space— marked by the STKEND system variable — and the bottom of

Memory
growth

NICHOLAS KENNEDY of Bel-
fast., Geoffrey Hulme of Stoke,
and Gareth Rieiey of Notting-
ham, are interested in adding RAM to
their ZX-81s or Spectrums. They ask
questions like: What are the advan-
tages and problems of using a 64K
RAM on the ZX-8I? Can 16K Spec-
trum programs be loaded into the
48K machine? Can 16K ZX-81
RAMs be used on the Spectrum?
Why is there a difference in price
between add-on RAMs for the Mod-
el One and Model Two Spectrum*?

In the face of such a barrage I con-
tacted Stephen AdaitiS) who specialises
in dismantling Sinclair computers for
fun, for the latest information. Most
people know that 64K of total memory
— i.e., ROM and RAM — is the most
which can be used with the 2-80 micro-
processor without special paging facili-
ties. In the ZX-81 the bottom 8K of
memory is reserved for the ROM — the
set of machine code instructions which
give the machine its character. In the
un expanded machine the next 8K is
absent and then there is JK of RAAl at
addresses 16K to 17K.

When a 16K RAM pack is added it
displaces the IK of RAM to occupy
addresses l6Kto 32K, The implication
of that design is that Sinclair intended
originally to release a new ROM with
enhanced facilities to occupy addresses
to 16K.

In fact, it has never done so but other
manufacturers have stepped in to fill
the gap with graphics units and assem-
blers; 16K and 32K memories are also
available which occupy addresses 16K
to 32K and 16K to 48K respectively,

In either case, all the extra memory is
available directly to the Basic system;
64K RAMs are available of which 4SK
lies between addresses I6K and 64K
and is available for normal use. Another
8K replaces the "missing" 8K of ROM
but that part of memory can be
FEEKed and FOR Ed only from Basic.
The final 8K is present but unused,
which means presumably that the man-
ufacturer also has some future appli-
cation in mind.

The memory situation for the Spec-
trum is equally complicated but for
rather different reasons. In this machine
the ROM occupies to 1GK and the

ContmucJ on fwgr 110

108

SINCLAIR USER Annual 1984

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When you get your breath back you'll he running
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■ho the future you'tf find that Berth Is a very
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standard I6K RAM occupies the re-
maining area up to 32K. The easiest
way to add more memory is to return
the machine to Sinclair with a suitable
cheque and it will do the job, but that
means doing without your machine for
a time

Add-on memory is available from
other manufacturers but Sinclair has re-
designed the circuit board completely
since its original launch and so it is
necessary to determine whether your
machine is an early version — model
one — or a re-designed version — model
two.

Most model one machines have grey
keys, whereas model two has light blue
keys. To be certain which model you
have you should look into the machine
through the slot in the rear where the
edge connector is situated,

If you have a I6K model one you will
see a vacant 16-pin socket on the printed
circuit board lying to the left of the slot
and about two centimetres from the rear
of the machine.

If your machine is a 48K model one
the 16-pin socket will not be vacant but
will act as the connector between the
main printed circuit board and a subsid-
iary board on which the extra memory
and decoding chips are mounted.

In that case you will also see seven
circular capacitors, each rather smaller
than a halfpenny piece, mounted on the
subsidiary board in a line facing the rear
of the machine.

The 16-pin socket is not present on
the model two because there is space
available on the re-designed main print-
ed circuit board for the extra memory
and decoding chips- Instead s the very
large Z-80 microprocessor chip is
clearly visible through the slot, lying
approximately below the 9 key on the
keyboard.

The reason for the price difference

for add-on memory between model one
and model two machines is apparent.
To extend a model one the necessary
chips must be mounted on a suitable
board to be located above the main
board. To extend a model two the
necessary chips need only to be inserted
in the sockets already provided on the
main board.

It is not possible to plug a ZX-81
RAM pack directly into a Spectrum,
although at least one company now
markets a small adaptor to allow you to
do so, thus giving 32K of RAM with a
1 6K ZX-81 RAM pack or 48K of RAM
with a 64K ZX-81 RAM pack.

Programs written for a 16K or 32K
Spectrum should work without modifi-
cation on the 48K machine and it is safe
to assume that all 16K programs avail-
able commercially will run on the larger
machines. Of course, the converse is not
true; it is most unlikely that a program
written for 48 K would function on a
smaller machine.

Henry Evan son of Bromborough
writes: I wish to use the 48K soft-
ware packs but the first I purchased
will not load. How can I check that I
have received a 48K Spectrum and
not a 16k machine by mistake?

The answer is to check the high byte
of the P-RAMT pointer at address
23733 by entering:
PRINT INT (PEEK 23733/4)-15; "K M

The machine sets the contents of
23733 to 255 - or 127 on the 16K
Spectrum — when it is plugged-in and
the line above performs a simple calcu-
lation and PRINTS 16K or 48 K as
appropriate.

At any particular time a user may run
out of memory, Michael Fawcett has a
problem with his ZX-81 in that regard.
He writes: When I get near to the
end of entering a particular pro-
gram the cursor disappears and
whenever a key is pressed sub-

sequently, a letter disappears.
What is wrong?

Many ZX-81 users will recognise in
Fawcett' s remarks that he is running
out of memory. The only guaranteed
solution is to buy an add-on RAM pack,
although a certain amount of space can
be saved by deleting REM statements
and shortening PRINT statements.
The Spectrum, incidentally, emits a
low-pitched buzz when memory is
short.

A check on the amount of memory
left can be made at any time by entering
the following REM at line I: L

I REM RESERVE SOME SPACE

and POKEing the following numbers:

33, 0, 0, 57, 237,91, 28, 64,

167, 237, 82, 68 3 77, 201

into locations 16514, 16515 . . . 16527

(on the ZX-81).

The equivalent locations on the Spec-
trum are 23760, 23761 23773 and

the numbers to be POKEd are the same
except that 101, 92, should be sub-
stituted for 28, 64.

In each case a short machine code
routine is loaded into the space reserved
in the REM statement and then the
amount of memory left can be PR IN Ted
by entering:

PRINT USR 16514 - 24; "BYTES"
or in the case of the Spectrum:
PRINT USR 23760 - 24; "BYTES"

Robert King of London asks: I have
a program which works well on my
friend's Spectrum but always
crashes on mine. I suspect a fault in
the RAM. Have you a program
which checks each RAM location in
turn?

Checking RAM involves setting ev-
ery bit of every byte, checking that it
remains set, and then re-setting every
bit and checking that it then remains re-
set. Setting every bit in a byte is equiv-
alent to POKEing 255 into that byte.
Similarly, re-setting every bit is equiv-
alent to POKEing in 0.

Obviously it is not possible to POKE^
numbers into every memory location
while the machine is running, because
the computer will crash, but a partial
check can be made by testing every
location in the spare area of memory.

The program in table two runs such a
check. It can be loaded using an assem-
bler or using the simple hexadecimal
loader listed in table three.

The program checks every location
up to the bottom of the stack and
returns the address at which it stops —
about 32575 in the 16K machines and
65343 in the 48K machine when they
are working correctly.

LIU

SINCLAIR USER Annua! 1984

Storing data in
string arrays

UNDERSTANDING data stor-
age and arrays is something
which puzzles many readers.
Norman Disley of Cheshire has a
collection of about 50 music cassettes
which he wishes to catalogue on a Spec-
trum. He writes: Each tune would
require six or more entries — title
name, soloist, and as each cassette
contains about 30 titles the collec-
tion would use almost all of the
9999 lines of the Spectrum, leaving
little room for later insertions.
What can I do?

Several people have written outlining
the same idea of using the 99°9 pro-
gram lines available to store up to 9999
items of information. The technique
has the merit of simplicity in use but
there is no possibility of writing a pro-
gram to search^ sort or PRINT the
informal ion.

The conventional technique is to
store the information in a numeric or
string array. The length of a numeric
array is 4 + 2* number of dimensions
+ 5* total number of elements.

ThuSj for example, the two-dimen-
sional array N(2, 5) which contains 10
elements occupies 4 + 2*2 + 5*10 = 58
bytes.

A string array occupies 4+2* num-
ber of dimensions + total number of
elements and so Zs (2, 5) uses
4 + 2*2+10=18 bytes.

Disley wishes to store string data and
so allowing 10 characters per entry, six
entries per tune, 30 tunes per cassette
and 50 cassettes, he would need to
declare a string array:

2^50,30,6, 10)
This would occupy

4+2*4 + 50*30*6*10-90,012 bytes
There are about 10,000 bytes avail-
able to the user in the 16K Spectrum
and about 42,000 bytes in the 48K
machine. Clearly Disley will hot be able
ro hold all the data in the machine at the
same time in that manner. The problem
would still arise even if he were to use
program lines, as each character in the
line occupies one byte and there is an
overhead of six bytes per line.

Space could be saved by using fewer
than 10 characters per entry, perhaps by
using abbreviations. Alternatively, the

six entries per tune of 10 characters
each — 60 characters in all — could be
combined into a single entry of, say, 30
characters so that less space was wasted
on trailing blanks.

A more sophisticated solution would
be to hold all the information in one
long string array and to use a second,
numeric, array to point to the location
in the string array at which each entry
began. The slicing technique described
in ZX Spectrum Bask Programming
could then be used to select a given
entry. The following program demon-
strates the method:

10 DIM P(I01): REM DECLARE
POINTER ARRAY

20 LETPZ-1

'I want to enlarge

the array

in a program'

30 DIM Z${1000): REM DECLARE

STRING ARRAY
40 INPUT "ENTER DATA"; A$
50 IF P(PZ) + LEN AS > 1000 GOTO

100
60 LET P(PZ+1)=P<PZ + LEN AS)
70 LET Z$ (TO P(PZ+ l)) = Z$

(TO P{PZ)) + AS
80 LET PZ = PZ+1
90 IF PZ< 102 THEN GOTO 40

John Brookes of Bromsgrove writes:
The books are generally easy to
read but none of them explains
arrays sufficiently clearly for us
wooden-headed types. Can you
help?

Most tasks performed by computers
comprise reading information into
memory, manipulating the information
according to a program of stored
instructions, and writing the infor-
mation out of memory.

The information stored in memory
must be organised in some convenient
fashion so that the person who writes
the program of instructions can do his
job. Most high-level languages allow
the programmer to declare variables of
various kinds so that different types of
information can be stored and treated in
appropriate ways.

The ZX-81 and the Spectrum each
allow six types of variables — numeric
with a single character name; numeric
with a multiple character name; control
for a FOR-NEXT loop; string; string
array; numeric array.

The first two types are identical in
use, as they can each store only a single
positive or negative number. Most pro-
grammers try to give a name to a vari-
able which reminds them of the
information it holds. For example, a
bank account program might hold the
current balance in a variable called
BALANCE.

In many programs similar infor-
mation is to be stored concurrently and
in that situation the program is also
likely to become unnecessarily cumber-
some because the same operation must
be performed on many variables, each
with a different name and therefore
requiring a separate piece of code.

The bank account program might be
required to store [he .mmum spent
using each of 30 cheques in a cheque
book. The amount spent using the first
cheque could be stored in a variable
called CHEQUE. The same variable
could not be used to store the value of
the second cheque because only one
value can be stored in a numeric vari-
able.

The act of entering the second value
over-writes the first value, causing it to
be lost, hence the programmer must
think of a new name for the second
cheque. Most programmers would run
out of inspiration before they had
named all 30 cheques.

One way of naming all 30 which
would not require too much eflbrt
would be to call them CHEQUE I 3
CHEQUE2, CHEQUE3. Thai is the
idea of an array, Sinclair arrays are
restricted to single-character names

10 PRINT AT 0J l;"CHEQUll: m ;

20 PRINT AT 2,0; 'ENTER CURRENT
BALANCE"

30 INPUT BAtANCH

40 DIM Q30)

50 PRINT AT 2,Q;"ENTER BACH
CHEQUE IN TURN"

60 FOR I = I TO M

70 PRINT AT 4,0;"CURRi:N I
BALANCE = "; BALANCE

80 IK PUT QI)

90 LET BAIANCE-BALANCE-CCI]
100 NEXT I
110 CLS

120 PRINT 'CHEQUE NO ","V Mil
1 JO FOR I - 1 TO 30
140 PRINT 1,Q1>

150 IF PEEK 16442-3 THEN SCROLL
160 NEXT!

Table 1. A simple cheque book
program.

SINCLAIR USER Armwl 1984

\V\

only but that is a small price to pay for
the flexibility they provide.

Table one shows a simple cheque
book program which uses an array, C,
of length 30 to hold the value of each
cheque as it is entered. The program
also shows the use of another variable,
I, to count through the array selecting
each element of the array in turn. When
all the cheques have been entered the
program prints the value of each in
turn,

Simon Smith of Battersea, London
has a more complex question concern-
ing arrays. He writes: I have a ZX-81
and recently bought a 64K memory
to replace the 16K RAM pack I had
previously. I now want to enlarge
the array in a program which in-
dexes my record collection to make
use of the extra memory space. Is
there any way of doing so, short of
copying the data to another array?

Defining a new array and copying the
data across using a FOR-NEXT loop
would certainly be the easiest way of
dealing with the problem. The disad-
vantage is that the new array can occupy
only the space which is not used by the
old array; hence when the old array is
deleted — by DLMensioning it to zero
— the memory space it occupies re-
mains unused. If the old array was 12K
bytes long and a further 32K bytes of
memory was added, the new array could
occupy only 32K of the total of 44K
bytes available.

There is no Basic command to make
an array grow to fill the remaining
memory space and so I have written the
machine code routine listed in table two
to do the job. The routine can be loaded
into a REM statement forming the sec-
ond line in a ZX-81 program using a
hexadecimal loader. For example:
10 REM XA$
20 REM AT LEAST 10$

CHARACTERS
30 FOR 1=16523 to 16630
40 INPUT ZS

50 IF Z$= U S" THEN STOP
60 PRINT Z$- l < "■
70 POKE I,16*CODE Z$ + CODE

Z$(2)-47G
80 NEXT I

To load the machine code routine,
run the loader and enter each pair of
hexadecimal codes in turn. Be very
careful not to make mistakes because
the program makes no error checks.

To use the routine to double the size
of a string array called A3 make the first
program line a REM statement contain-
ing an "X" followed by the name of the
array, i.e., AS as in the loader. Then
POKE the factor by which you want
the array to grow into the first byte of
the REM statement. In that case the
array is to grow by a factor of two so you
should enter:
POKE 16514,2

Then call the machine code routine by
entering:
RAND USR 16523

Table 2, A ZX'Bl routine to enlarge

an array dynamically.

Hex code

Assembler code

Comment

Ht* cad*

Aiaembler code

Comment

un«

LD AJ165N)

Return if

09

ADD HL n BC

Set HL to

FEB]

CP 1

parameter

18 2B

JH C,0

new length.

OS

RETC

U itta.

DI

POP DE

21 SJW

LD HLJ65I5

So CH-ADD.

E5

PUSH HL

22 mo

LD<L6-106},H1.

M

AND A

CD 1C II

CALL LOOKVARS

Rod amy,

EDH

SBC HL.DE

Set BCro

D8

RETC

ReUirn if

44

LD H,H

irtff*iiae

1 CO

RETNZ

nunicjjL.

U)

LDC.L

in kngia.

?E

ID AJlHH

Return

El

POPHL

FEW

CP 128

if

E)

EX {SPfcHL

Set !U i.i

Dfl

RETC

Kring,

E5

PUSH HI.

•ddresi or

21

INC HI

Sci A in

H

ADD HL.DE

end of array.

21

INC HI

number of

23

INC HL

2)

INCHL

dimension*.

CD 9E 09

CAU MAKE SPACE

1 i.iipe array.

7E

LD A,(HI.|

El

POP 111.

CB27

SLA,A

Multiply hi

[j|

POP DE

06W

LD $£

two ind

73

LD (HL^E

Insert new

CBIO

KLB

add one,

23

INC HI.

lengrb.

3C

INC A

tnmfkr

72

LD [HL),E>

4F

L.li C,A

ioBC

23

INC HL

39

DEC HI.

III. points to

21

INC HI.

56

LDD,(HL)

length

IE

LDCJHL,

Set BCio

3B

DEC HI.

DEn

21

INC HL

Hm

SB

LD E^HL)

old length

W

LD Bv(HL)

dimension.

E?

PUSH HI

Save

IIMOO

LD DE,0

Calculate

□5

PUSH n£

FB

EX DE.HL

new filsc

EB

'H,HL

Set DE

1A 82 40

LD A,{1^14)

diffienrion.

AT

AND A

to aid

0¥

ADDHUBC

ED 42

SBC Hl„BC

dou lenph.

513

DEC A

EB

EX DE.HL

II- 00

CP0

21 IM 00

1 D BXJJ

Calculate

2S FA

IK NZ,-6

1AS2 40

LD AJ16SH)

new dm

EB

1 X NliJtL

A7

AND

length

72

LD (Hl.),D

Store new

19

ADD HL,DE

21

DEC IIL

fim

3913

iRC„5i

Jump on overflow

73

LD(KL,.E

dimrnnon

an

DEC A

c*

RET

FE0B

CPC

El

POP HL

If (ivrrfloii-

IB ] I

1* MZ,-8

El
C9

POPHL

US' I

then return.

Both the total length of the array and
the size of the first dimension will grow
by the factor specified at address 16514.

The routine makes a number of error
checks, ft will detect if the named vari-
able does not exist or is not an array. Ii
also ensures that there is sufficient room
in RAM to enlarge the array by the
factor specified.

The routine makes use of two ROM
routines. The first is LOOKVARS
which is located at 4380 decimal —
111C hexadecimal.

That routine finds the local ion in the
variable area of the variable pointed to
by CH-ADD and returns the address in
the HL register pair, The second ROM
routine, MAKE SPACE, inserts BC
bytes at the address pointed to by HL,

The operation of the routine can be
checked by adding the following lines to
the hexadecimal loader:

1000 DIM A$<2,3)
1010 LET A$<1)= , *ABC"
1020 LET AS(2)="DEF rt
1030 GOSUB 2000
1040 POKE 16514,2
1050 RAND USR 16523
1060 GOSUB 2000
1070 STOP
2000 LET W = PEEK

16400 + 256*16401
2010 FOR I=W TO W + 21
2020 PRINT LPEEK I
2030 NEXT I
2040 PAUSE 32768
2050 CLS
2060 RETURN

Execute the test program by entering:
RUN 1000

The program declares an array AS
and PRINTs the contents of the first 22
bytes of the variable area where the
array is held.

The user can note the contents of the
display and compare it to the format of
an array as shown on pages 173 and 174
of ZX-81 Basic Programming.

The program then doubles the size of
the array and displays the first 22 bytes
again. The user will see that the total
length of the array has increased appro-
priately and that the size of the first
dimension has doubled.

With a little care the routine can be
adapted to run on the Spectrum, The
ROM routines LOOKVARS and
MAKE SPACE are located at ,10418
and 5717 respectively, CH-ADD is at
23645 — 5CSD hexadecimal.

it is also necessary to alter the
addresses at which the scale factor and
the name of the array are stored.

II-"!

SINCLAIR USER Annual 1984

FOOTBALL POOLS
PROGRAM

• The program lists out, m order of preference, ftie sixteen most
likely score-draws: also the sixteen most likely homes, draws

and aways.

I! picks Out the results on the bookmakers FIXED ODDS
coupons thai have been given over-generous odds Calcu-
lates your expected profit 1

The program will be initialised to the English and Scottish
league tables. You will be able to update these league ladles
week, by week 35 results come in — or enter a complete new
901 of league tables in other words, the program will never
become 'out oi date"'

t All programs are recorded ori a top quahly cassette (usually
Sony} and are accompanied with an instruction leaflet giving a
bnet explanation of the theory.

Available for the ZX-81 16K (Price £8.95) and the
ZX Spectrum 48K (Price £9.95) from:

HARTLAND SOFTWARE

(Oept, A), 3 Penzance Place,
London W11 4PA.

KERNOW SOFTWARE
SERVICES LTD

PRESENTS

THE KERNOW SOFTWARE

EXCHANGE CLUB

Exchange your unwarned commercial SPECTKIIM tapes
ai low cost wiih no time limits impOMd

• Membership only £4,00 for 12 months,

• Exchange only £1.45 inc P&P,

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• Exchange what you like, when you like.

• Return of post service.

Join today by clipping the coupon below or send s.a.e, tor
further details.

^} YES, please enrol me as a member of the exchange
club. I enclose my £4 cheque/postal order.

I aho enclose |_| tape(s) for exchange, please send rue
the current availability list and exchange voucher^)
(£1.45 per exchange).

Name.,

Address .,....* *.,.... „ ,.

........ ....Post Code... ,

Send to:

THE KERNOW SOFTWARE EXCHANGE CLUB

(DEPT. SA)

55 ELIOT DRIVE. SI GERMANS,

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r

BUSINESS USERS

SPECTRUM 48K
ACCOUNTS PREPARATION

Produces Prime Entry Listings, Nominal Ledger, Trial Balance,
Profit and Loss Account and Balance Sheet with supporting
schedules. 73 nominal ledger accounts and automatic VAT
calculations,

Sole Trader/ Partners hip (Up to 41 £25 00

Limited Company C25-QQ

Combined Price £35-00)

SALES AND PURCHASE LEDGERS

Produces day book, salesi'purchases and VAT analyses,
debtors/creditors listings and statements. 250 accounts and
1000 monthly transactions. Automatically calculates
VAT, £25.00

ZX-81 16K

ACCOUNTS PREPARATION

31 nominal ledger accounts

Sole Trader £17.50

Limited Company CI 7 50

{Combined Price €25,00)

SALES AND PURCHASE LEDGERS

Produces day book, sales /purchase and VAT analyses,

debtors/creditors listings, statements.

50 accounts and 20O monthly transactions.

Sales
Purchases

£20.00

£20 00

(Combined Price £25,001

AH programs have been professionally developed and are
being used by practising accountants and small businesses.
Supplied on cassette with operating instructions.

P.O.

Fult derails:

HESTACREST LIMITED

Box 1 9, Leighton Buzzard, Beds. LU7 ODG
Tel. 052-523 785

SPECTRUM

DUAL FUNCTION
JOYSTICK INTERFACE
£13-95inc

WHY PAV £35 FOR 2

INTERFACES WHEN VOU CAN

SUV OUR DUAL INTERFACF FOR

JUST £13.95 INC.

FEATURES

* Compatible with any software that
list the Kempsion Joystick

♦ Compatible with any software that uses Cursor keys

• Compatible with most Psion/Melbourne House games eg
Terror Daktil, Horace Goes Skiing etc

• Allows the use of AtOfi/Le Stick type joystick.

• Eight directions can be programmed in simple basic.

♦ Free drqw programme and full instructions supplied

STANDARD INTERFACE FEATURES

Same as Dual Interface
rBut only compatible with any software that
Kempston Joystick

ists the

ZX-81 /SPECTRUM

LOADING PROBLEMS SOLVED WITH

The CODER as reviewed in the Sinclair User
August 'A3 £9.95 INC

DUAL INTERFACE . £13.95 inc

STANDARD INTERFACE £ 1 95 ihC

£1 discount it joystick ordered with any interlace

eg DualMnt & joystick £19 45 inc

Send Cheques/P.O to:

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Overseas orders add £2. DO

SINt l .UK lM'R rfwiMiJ 1884

II3

Number crunch
on Sinclair

AQUESTION often posed by
those writing an educational pro-
gram who have incorporated a
number of problems into their program
and want to p resent , say, half of them in
one session, is asked by Steven Multby
of Northampton. How do you tell the
ZX-81 to think of five random
whole numbers between 1 and 10
without the risk of repetition?

The obvious answer to his question is
a routine of the form:
10 DIM A(5)

20 LET A(I)=I + INT(RNDM0)
30 PRINT A(l),"";
40 FOR 1=^2 TO 5
50 LET R= 1 +INT{RND10)
60 F0RJ=1 TOM
70 IF A(J) = R THEN GOTO 50
80 NEXT J
40 LET A(I)=R
100 PRINT A(I); !t ";
110 NEXT I

Array A is used to store each selection
and if a repetition arises it is discarded
and a fresh random number is drawn.
The routine works well for small sam-
ples but becomes progressively slower if
the number of samples is increased.

To see the effect, try changing lines
10, 20, 40 and 50 as follows, to simulate
the effect of drawing all 52 cards from a
pack in random order:
10 DIM A(52)

20 LET A(1)=I + INT(RND*52)
40 FOR 1=2 TO 52
50 LET R=1+INT(RND*52)

Each selection tends to take longer
than the previous one because the
chance of choosing a number which has
appeared previously increases. In choos-
ing the final number, the ZX-S1 must
select the correct number out of 52

5 LET A- 1

10 PRINT "BYTE"; TAB 6;

■CONTENTS"; TAB 16;

CHARACTER"

1 5 LET S = FKEK 23635 +256*PEEK

23636

20 FORI = STO S+20

25 PRINT I;TAB S;PEEK I;TAB

2fr,CHRS PEEK ]

30 NEXT I

Table 1. A Spectrum program which

looks At the first 21 bytes of the program

are el

possibilities, which can take a very long
time.

A much more elegant solution is to
use a routine which mimics the act of
shuffling a pack of cards, i.e., create an
array containing all 52 possibilities in
order and then randomise the locations
of each element of the array in turn. A
suitable routine of this form for
Maltby's problem is:
10 DIM A{10)
20 FOR I - 1 TO 10
30 LET A(1) = I
40 NEXT I
50 FOR i=l TO 10
60 LETR = I+INT(RND*I0)
70 LETS = A(R)
80 LETA(R) = A(I)
90 LET A(I) = S
100 NEXT I
110 FOR 1=1 TO 5
120 PRINT A(I)
130 NEXT I

Lines 10 to 40 set up the array, lines
50 to 100 swop each element in turn
with another element selected at ran-
dom — the equivalent of shuffling cards
- and lines 110 to 130 PRINT the first
five elements of the randomised array.
Alan Sheldon of Aylesbury asks' It
would appear that numbers in the
program area of memory are fol-
lowed by additional information
which does not appear in listings. Is
that so and if so why?

Sheldon is correct as can be seen by
entering the Spectrum program listed in
table one. The program will also work
on the ZX-81 if line 15 is altered to
read:

15 LET S= 16509
Line 5 is a dummy line, the purpose
of which is to allow the user to study the
appearance of numbers in programs.
When the program is RUN it looks at
the contents of the first 2 1 bytes in the
program area and displays them on the
screen. The results for the Spectrum are
shown in table two.

The first two bytes contain the line
number (5) and the next two bytes
specify the length of the remainder of
the line (1 1 bytes). The next four bytes
hold the character code for the first line
of the program:

LETA=l

The character codes vary slightly be-
tween the two machines. For example,
the code of the letter *A* is 65 on the
Spectrum and 38 on the ZX-81 al-
though the code for the 'LET* is 241 on
both machines. The full list of character
codes is given in appendix A of the
manual supplied with each computer.

On the Spectrum the next byte con-
tains 14, That is not the code for the
end of a line, as might be expected, but
instead it is described in appendix A of
the manual as ''number". In fact, the
byte acts as a signal to the LIST and
other commands to ignore the byte and
the contents of the five locations which
follow it. Hence there is no indication
in listings of the program that those
additional locations are used. The line
is terminated by the next byte which
contains 13 — the ENTER character.

On the XX-fil the character codes are
different but the effect is the same. The
location containing the code for T is
followed by six "hidden" bytes, which
do not appear in program listings.

Some clue as to the purpose of those
hidden bytes can be gained by replacing
line 5, the dummy line, by another line.
Try, for example, RUNning the pro-
gram with

5 LET A = 2.7
as the dummy line. The characters Tor
the number "2.7" occupy three bytes,
not one as for the number 14 1", but
again the number is followed by six
hidden bytes. A few minutes' experi-
mentation will show that whenever a
number appears within a program six
hidden bytes follow.

The reason for the use of the hidden
bytes is that the ZX-81 and the Spec-
trum do not store and manipulate num-
bers in the character form in which they
are displayed. They are converted into a
"calculation" format and all additions,
multiplications and so on are undertak-
en on the numbers in this format, when

Byte

Contents

Character

2 3755

?

2 3756

5

?

23757

11

?

23758

?

23759

241

1 !' 1

23760

65

A

23761

61

-

23762

49

1

2 3763

M

?

23764

?

2 3765

?

2 3766

I

i

23767

}

23768

}

237C*

13

Table 2.

The first

1.".

lines of the Krcen

display

produced

w

lien the Spectrum

program in Table

1 is executed.

114

SINCLAIR USER Annual 1384

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the result of a calculation is PRINTed it
must be converted into characters for
display on the screen. Similarly^ the
character form of a number entered by
the user must be converted to the calcu-
lation format before a calculation can be
executed.

All such conversions take time. To
accelerate the execution of programs the
conversion to calculation format is un-
der taken immediately a number in a
program line is entered from the key-
board. The resulting five-byte form is
stored in the hidden bytes. The use of
this technique enables a considerable
saving to be made in the time taken to
execute a program, particularly if num-
bers are included within FOR loops, in
which case the same conversion would
otherwise be undertaken many times.
Of course, the time taken to deal with a
program line entered from the keyboard
is lengthened but not to an unaccept-
able extent,

Hugo Cassidy of Dorchester asks;
Can you explain the method of en-
coding numbers on the Spectrum?
Given that it is necessary to convert
numbers from decimal to binary, it is
logical to use a binary format which is
efficient and therefore fast for the com-
puter to use. Two separate formats are
used on the Spectrum, a special format
for integers, or whole numbers, lying in
the range -65535 to 65535 and a float-
ing point format for all other numbers.
The ZX-S1 uses the floating point for-
mat only.

The integer format is the simplest to
understand and so I shall explain it first.
A suitable number, N, is converted to
the five-byte form by setting the first
and fifth bytes to zero and using the
second byte to indicate the sign of the
number, for positive, 255 for nega-
tive. If the number is positive the value
is stored in the third and fourth bytes as;
Third byte = N-256*INT (N/256)
Fourth byte- INT (NY256)
If N is negative the two bytes contain:
Third bvte = 65536— N-256*

10 INPUT N

20 PRINT N;' "j

JO LET A=PEEK 2}fi27 + 256*PEEK

23426
40 FORI-A+I TO A+S
50 PRINT PEEK I;" ";
M NEXT [
70 GOTO 10

Table 3. A Sprcirum program id inspeel
the flve-hyit ftirm of number entered by
the users.

To run the program on the ZX-81 change
line 30 to read:

50 LETA-FEEK 16400+ 2«*PfiEK
16401

INT «65536-N)/256)

Fourth byte = INT ((65536-N)/256

The principal advantage of the use of
integer format is that for positive inte-
gers the third and fourth bytes are in the
form the Z-80A microprocessor uses
when addressing locations in memory.
Commands such as PEEK and POKE
are executed much faster than they
would otherwise be if the more complex
floating point form were used to store
the addresses to which they refer. The
format also enables the calculator rou-
tines in the ROM to execute much more
quickly when calculations involving in-
tegers only are performed.

The program in table one can be used
to inspect the positive integer form by
varying the first line. For example,
entering:

5 LETA = 47
will show that 47 is held as 0,0,47,0,0,
The negative version cannot be inspect-
ed using this program because all num-
bers are stored in their positive form in
the hidden bytes. If a number is preced-
ed by a negative sign it is negated when
the line is executed.

The program in table four gives the
five-byte form of any number, positive
or negative, entered from the keyboard.
The program PRINTS the contents of
the first item in the variable area, that is
the number N entered by the user from
the keyboard, because it is the first
variable declared in the program.

Note that the program should be
initiated by entering RUN rather than
GOTO 10 because doing so will cause
the variables area to be C LEA Red, thus
ensuring that N is the first variable.

The floating point form is designed
to provide the computer with a system-
atic method of retaining as much accu-
racy as possible in any given
calculation. Some numbers cannot be
specified completely in decimal form.
The fraction one-third in decimal form
consists of 1,3 followed by an infinite
number of threes so that expressing it as
1,3333, for example, is almost, but not
exactly, correct. The same problem oc-
curs when binary arithmetic is used.

The solution is to retain only the
most significant digits at each stage in a
calculation. Provided more significant
digits are retained than are required in
the answer then in all but the most
exceptional circumstances the calculat-
ed result will be accurate enough for
practical purposes.

The program listed in table five cal-
culates and PRrNTs the floating point
form uf a number entered by the user
The line numbers have been set so that
it can be placed in memory at the same

time as the inspection program in table
four. By entering the same number into
both programs the user will see that the
calculation is correct.

The program has two parts. The first
stores the sign, S, of the number, X,
entered by the user. It then multiplies
the absolute value of X. successively by
2 until the result exceeds 2 raised to the
power 31 or 21474383648, The number
of multiplications executed is stored in
N. The new value of X then lies neces-
sarily between 2 to the power of 3 1 and
2 to the power 32 and so the integer part
of the number can be stored exactly in
31 bits.

Thus by discarding the fractional
residue the number can be stored in
four bytes, each containing eight bits
with one bit left over to hold the sign of
the number. The four bytes together are
called the mantissa.

The second part of the program cal-
culates the values held in each of the
four bytes and stores them in the varia-
bles A, B a C and D and then PRINTs
the variables. An adjustment is made to
the value of A depending on the sign of
the original number. In eflcct A is less
than 128 for positive numbers and
greater or equal to 128 for negative
numbers.

The fifth byte of the floating point
form is used to store the exponent, that
is the number of times that the mani-
tissa must be divided or multiplied by 2
to place the decimal point in the correct
position in the number.

The program calculates that number
using N, the number of multiplications
made originally. The result is adjusted
by adding 160 so that numbers greater
than or equal to 128 and numbers less
than one have exponents less than 128.

210

LETM

-o

220

INPUT X

230

LETS*

= SGN X

240

LETX

"AHS X

250

LET X

■2*X

260

1 k f N

= N+I

270 IF X<2J474B364S THEN GOTO

30

280

LET A.

= INT {XI 167 7721 fij

2TO

x-x-

67772 16* A

300

LET H =

= INT (X/65 Stop

310 LET X

= X-65536*B

320

LETC

= INT (XJ256)

330

LET D

=X— 25G*C

344)

PRINT

■EXPONENT- "; 160-N

350

PRINT

"MANTISSA -";A-

I36*(S-

l)T "jB;" ";i:r ";D

Table 4. A

ypivrrum artgnm i<> eatea>

last

and PRINT rm: Howling point form of

a number entered from the keyboard,

116

SINCLAIR USER Jtitnual ?984

User
of the Month

During the last 12 months we began a new

series in which we interviewed interesting

users. We reprint some of them to indicate

the wide variety of purposes for which the

Sinclair machines are used.

004

SINCLAIR USER A'tatmi ISM

117

Stephen Sowerby is a member of the Olympic pentathlon squad.
Claudia Cooke discovers how he makes time for training

Leading athlete's quest for
gold is boosted by ZX-81

NTERNATIONAL athlete Ste
phen Sowerby swears by his ZX-
81 Without it, he says, finding the
time to train is much more difficult. At
28, Stephen hopes to make his Olympic
debut as one of the four-man modern
pentathlon squad in the 19S4 Games in
Los Angeles.

On top of that, he runs two busin-
esses near his home in Yorkshire and
spends what precious spare time he has
on his hobbies of photography and wine
and beer making. He says:

'Tin impressed with the little beast
— the ZX-81, I bought it last December
with the idea of upgrading it as soon as I
had mastered it but I don't see any need
now. It does everything I want it to do".
Before buying his computer,
Sowerby had had no contact with any-
thing more complicated than a pocket
calculator but he decided that anything
which could speed his office workload
would be invaluable.

"First, I waded through the book and
made it to work. Then I wrote my first
program, a simple one for VAT check-
ing which has been fantastic. I found
that it was really easy if you used
common sense. Of course, there were
headaches along the way but 1 sat down
and scratched my head and it ail came
out right.

I am pleased to say that I have never
bought a commercial program. I have
written 10 of my own; the longest is for
helping me to do the accounts. The
amount of time it saves is incredible. 1
buy the computer magazines and use
some of the programs in them. Apart
from being fun they can be really help-
ful, too, because sometimes you dis-
cover you have been using five lines
where someone else has discovered a
wav to say the same thing in only one
line".

Running his business, as well as fit-
ting in his sports activities, means that
Sowerby is highly-motivated to do
everything in as short a time as possible
and the computer has helped.

'If I have all my work done by a
reasonable time in the afternoon t can
leave and fit in more training. So the
computer is helping me in my sport,

too". Modem pentathlon is a gruelling
combination of sports, the aim being to
find the best all-rounders. It embraces
swimming, running, fencing, shooting
and show pumping.

"Swimming was always my main
sport at school. I won at county level
and was in the national top 10 when I
was 17. Then I went to Carnegie Col-
lege, Leeds to train as a physical educa-
tion teacher for three years and I
stopped competitive swimming.

"My first job was as a teacher or
PE) swimming and outdoor pursuits at
Daniel Stewarts and Melville College,,
Edinburgh, where David Wilkie went
to school. I thoroughly enjoyed it but
after a year I had the chance to swim

competitively again with my old club in
Leeds and so I left teaching to give
myself more time.

"I was trying to be selected for the
Commonwealth Games and that meant
four or five hours in the water every
day. Then I entered the national biath-
lon — swimming and running. I had
entered it and won while I was still at
college and that time 1 won it again".

Sowerby is modest about that
achievement, saying that although he
was always the best runner at school, he
assumed that was simply because he
was fit from all the swimming.

The result of his success in the biath-
lon was thai the well-known pent ath-
lete, Jim Fox, suggested he should try

MS

SINCLAIR USER Annua! 1984

modern pentathlon. He had never
fenced before, never used a gun, and
scarcely ridden a horse but after only
four weeks' training, he entered his first
pentathlon in Cambridge and finished
second, despite the presence of seven
international modem pentathletes.

Since then he has not Looked back,
He has risen to international status and
travels the world to compete in events
as far afield as the United States— three
trips already — and several countries in
the Eastern bloc.

"1 love the travelling and there are so
many places I know I would never have
seen had it not been for the competi-
tions there. We were in Poland at the
start of the crisis and I learned a good
deal from that.

"They absolutely revere their sports-
men. There were food shortages and
queues everywhere but we had meal at
every meal and the autograph hunters
were all round us".

Sowerby is the only member of the
four -ST rang Olympic squad who does
not train full-lime but he sees that as nu
bad thing.

"■[ have ail the practice I need and in
i on$ 1 think my fob helps, because it
takes my mind off things, if you are just
training all the time you think only
about your sport and tl doesn't necessar-
ily do you any good. You just become
bored waiting for the next training ses-
sion.

"Iara glad [ tried the modern pen-
tathlon because I am so much happier
now. You have to be good at all five
events but if you don't do so well in one
aspect, it's not the end of The world.
When I was swimming, one race might
make or break me.

"Now J know I am the worst fencer
in the squad but I am training hard and
my running and swimming are strong
enough to compensate for it".

The businesses which Sowerby runs
stem from the enterprise of his parents,
Dennis and Elsie, who formed their
joinery company at Knares borough 30
years ago. As the business flourished, so
more and more customers needed glass,
so he formed Knaresborough Glass and
now runs both companies with the help
of his father.

Set in a small yard off the main street
in the sleepy Yorkshire market town,
with offices in a building known as the
hen hui, it is a far cry from (he glamour
of the international sports circuit but
Sowerby, who last year married a fellow
member of his swimming club, is happy
10 return to his her) hui and sit crouched
over his computer,

Since buying the ZX-81 he has also

bought an Olivetti printer driven by a
Memopak I/F which he keeps hidden
under the dK'tronics keyboard.

"The printer has been a marvellous
help 3 too. 1 have written a word proces-
sor program and I use it for all my
letters, for final demands, invoices, ev-
erything really, I begin to wonder what
I did without it".

Sowerby also sees potential for com-
puters in the world of sport. Already
they are used widely For results, as well
as for much of the administrative work,
but he cites a need for them in sports
such as fencing. Each fencer's sword

you can usually do it even when, as in
his case, it seems as if there will never
be the time.

**I do a great deal with my time but I
enjoy it all, otherwise I wouldn't do it. 1
will go on as a pentathlete until I stop
enjoying the training. When it becomes
a real chore and you don't want to do it,
that's the time to stop.

"Many people seem to think 1 must
be sacrificing a great deal for sport but I
don't see it as a sacrifice, because I
enjoy it.

*The only things I miss are smoking
40 cigarettes a day and probably being

'I have written a word processor program and
I use it for all my letters. For final demands,
invoices, everything really. I begin to wonder
what I did without it'

has a button on the end which lights at
certain points of contact with the oppo-
nent and is controlled by a box mechan-
ism. "That box mechanism often fails
and as there is only one company mak-
ing fencing equipment, there IS not
much we can do but a computer to
operate that mechanism could prove far
more reliable and 1 am sure someone
could make money producing it' T .

Sowerby feels the project is a little
ambitious for him, although he main-
tains thai if you want to do something.

overweight by the age of 18. So w he re's
the sacrifice?"

Financially, Sowerby has to be self-
supporting in his sport and thai can
mean sacrificing some expense — the
Spectrum, for example, for which he
sees no need in his office but on which
he loves playing games for its colour
and its extra graphics.

Any purchase not essential to him
stays in the shop but that could he why
both his business and his sporting ca-
reer ire proving so successful.

SINCLAIR L'SER Annual 1984

Hi)

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ftf-ASfSFW Mf YOUft WCROBRiPftf CASSETTE fpF THE SffCTflUM 48K

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BPECTROGRAPHIC!

(for Sinclair Spectrum 48k)
"A complete graphics toolkit. ..very easy to use.

documentation clear and concise"

(Personal Computer Woiidi

For Teachers For Games Enrrrusiasts For Artists For Everyone*

Exploits the Spectrum's superb graphics potential to the full:

• 1 1 graphics procedures

• Hi- arid lores sketch pads

• 8 sizes of text

• a mini-text editor

• colour WASH and PAINT

• create your own UDG characters

• SAVE displays on tape or PRINT on ZX Printer

• RELOAD displays into your own programs

send £6.90 for cassette and manual
'graphics software lor ZX81 also available*

send s.a.e. lor Our lull list o! games. ritfHfet, graphs and soenut*- -
Ful rooney-bacfc guarantee : Trade enquiries welcome

software

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Oept SA , 36 Femwood, Marple Bridge,
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for your Spectru

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Smart executive type case, purpose built, with locks, * IT" ■
special hinges and lift-ofTlid. (plusp&pj

Internal console allows neat installation or computer, power supply
and printer in Titled recesses. Provision for housing tape recorders up to

28cm x 15cm,

Aluminium switch panel eliminates constant removal of plugs for boih

save/load and power orr facilities and provides sockets for tape recorder

leads to allow operation in convenient position shown.

All internal wiring and leads supplied to allow easy plug-in installation
Case lid fitted with shock absorbing foam to protect components when

dosed and with retaining straps for neat storage of mains and T.V. aerial

leads.

SINCLAIR USER Annual 19X4

> Solves storage problems
l Computer angled for
--^convenient use

Avoids lengthy setting up
'Hues most of wiring
• Case and console moulded in
1 grained ABS plastic

Treelop DesiB^s, 61 Wklmotc Road,
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To: I rtetop Deigns

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Please supply cases a I

£47.43 each (iikI p&pand insurance)

Mycheqwt/P.0. fori

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ITyou arc MM satisfied wc shall t*t auir^e
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tase undamaged wild in 1* Jay*

121

122

SINCLAIR USER Ammai 1984

Each month we will interview a notable Sinclair user. Claudia Cooke
meets our first User of the Month, a retired shipbuilding manager.

Retiring to the sea, the
ships and his Sinclairs

ERIC AN SELL had been looking
forward to retirement and the
chance of a return to his native
Isle ofWight. Two years ago, at the age of
65 , he moved into a cottage near the sea
at Cowes with his wife, also an islander,
and intended to enjoy a quiet life of
reading, walking and watching television.
"Never in a million years did I think t
would learn something so new at my
age", he says, Yet in the six months since
his son gave him a ZX-81, he has become
hooked on home computers, to the extent
that he has just bought a Spectrum and a
new tape recorder to go with it.

"My son bought a ZX-81 but then he
moved to another computer and when he
visited me last summer he asked if 1
would like the ZX-81.

"At first I wondered what I wanted
with a computer. 1 could not see any use
for it. 1 had no interest in computers and I
did not realise how much fun they could

be".

Ansell, however, is a man who believes
in trying anything. * l Once my son had
left I started fiddling with it and became
absolutely hooked in no time It is the
sheer logic of it which appeals to me," he
says,

"You program a game from one of the
books and it tells you that you have made
two errors. Once you find those errors
you realise they are so logical and
obvious. It just takes common sense".

He admits it was two weeks before he
managed to program a game successfully
and he has not yet reached the stage of
writing a program.

"When I bought the Spectrum two
months ago, I found it much easier to
start because I already had some
knowledge of the ZX-81 and I have
become much faster at typing-in now.

"I used to have two pipes of tobacco in
the afternoon and perhaps read a little or
watch television. Now I become so
engrossed I forget all about my pipe and
everything else and I usually spend about
two hours, four days a week, with my
Spectrum*.

Ansell had had contact with computers
during his work as naval planning
manager with Swan Hunter in Newcastle

before his retirement but although he did
the critical path diagrams for the
computer printouts, his contact was
indirect.

"1 was always rather dubious about
large computers at work. If, for instance,
something is proceeding satisfactorily on
a ship and you put it through the
computer to find the best way, you might
have to wait five or sis days for an answer
but you can go and look at the ship and
have it corrected in one day".

He spent 35 years working for a local
shipbuilding firm at Cowes before
moving to Newcastle when the firm
closed. He began his career as a naval
draughtsman and then became a char-
tered engineer before working as a naval
shipbuilding manager. He loves ships
and everything to do with them and says:

"What amazes me about the Spectrum
is its ability to produce an almost perfect

'Never in a million
years did I Luink

I would learn

something so new

at my age 5

reproduction of, say, a destroyer, at the
push of a few buttons".

Ansell is keen to scotch rumours that
computers are for the young, or at least
for the under-ftus. He sees no reason why
that should be so.

"1 admit we are not so likely to have
contact with them in retirement. 1 doubt
that I should have discovered them if it
had not been for my son but 1 would
strongly advise any retired person with a
reasonable amount of common sense to
buy one straight away and play with it,

"It has given me an interest 1 never
expected to have at my age and my
brother in-law and I spent the whole of
Boxing Day together, playing golf with
the Spectrum".

It must be said that he is and always has
been an avid games player. Apart from
being a crossword fanatic, he also
subscribes to a weekly puzzle magazine

and likes board games as well.

!1 I remember when my two sons were
young, 1 would buy a new game every
Christmas and we would all spend hours
wit h it, sometimes making-up the rules as
we went along which, of course you
cannot do with a computer", he says.

As for progressing to even more
ambitious activities, he is happy with his
ZX-81 and his Spectrum, although he
says he may consider a 48 K Spectrum
instead of his present I6K,

The next step, of course, is for him to
begin writing programs, something he is
characteristically keen to try.

"I realise I need more experience first
and 1 am still enjoying the cassettes 1 can
buy, like Escape and Othello, but I would
like to program one or two games and 1
intend to try soon I find a great sense of
achievement in putting a program on
tape and having it correct".

Ansell is a young-looking 67. He wears
a smart blue velvet packet and sits in an
armchair within easy reach of a bowl of
assorted pipes, as befits any ocean- loving
man. On the other side is his Spectrum
and across the room there is the
presentation tray he received on his
retirement from Swan Hunter, listing all
the ships on which he worked.

The room is a stark mixture of the old
and the new, a combination which Ansell
has proved can work well together. All in
all, computers have enhanced his life in a
way he did not think possible and did noi
think he desired.

Retirement at Cowes, where he and his
wife were brought up, attending the same
school and marrying 43 years ago s is
something of an idyll and Ansell admits
that much as he enjoyed his years in
Newcastle, there was never any doubt in
his mind as to where he would set up his
retirement home.

"I think that had I left the island when I
was young, there might not have been the
same nostalgia but I was 50 when we
moved north and that is just too old to
begin putting down new roots",

Now, surrounded by sea, ships and a
host of books on both subjects, Ansell
and his computers are enjoying
themselves thoroughly.

SINCLAIR USER Annual 19S4

123

Claudia Cooke interviews a West Midlands doctor who is finding
ways of using a Sinclair computer to help educate his children

The smiling Spectrum
is Sophie's first choice

SOPHIE DENT has found life
enriched since [he arrival of a
Sinclair Spectrum in her home
six months ago. It is not that she has
spoken of that enrichment hut speaking
is altogether a problem, since Sophie is
only 18 months old.

Her shrieks or delight are sufficient
proof as she hurls herself towards the
keyboard for another intense session
with -one of her two programs. Both
were written specially for Sophie by her
father, Dr Tom Dent, who shares So-
phie's enthusiasm for home computers.

His other children, 1 0-year-old James
and Rhian, aged seven, both fell in love
with the Spectrum as soon as it arrived.
It soon became apparent that the role of
onlooker was too much for little Sophie;
she wanted to play, too.

At first her father was not sure how
he could write a program for Sophie—
for pressing specific kevs and refraining
from resting an elbow On the others is
difficult for any baby— but found the
answer with two colourful and instant-
ly-rewarding programs which operate
whichever key is pressed.

The fir$t allowed Sophie to produce a
smiling baby's face on the screen, some-
thing with which she could identify and
recognise from an early age. Her father,
a 35-year-old general practitioner, ex-
plains; "Faces are the first things to
which a baby responds and under-
stands. It was a happy, smiling face and
Sophie loved it".

The Second baby-proof program is
called Ghastly Graphics and has proved
equally popular with the older children.
Again, it operates by random pressing
of the keys. Gradually it produces a
mass of random graphics which eventu-
ally will fill the screen in a colourful
pattern. Each graphic is accompanied
by a note, making a cheerful tune which
further captures Sophie's attention.

Dent admits that at that stage the
Spectrum is just another toy to Sophie
and an expensive one were it not also
used by other members of the family.

He is already looking to the future,
when Sophie is three or four, and hopes
the Spectrum will be able to teach her to

read quicker and more efficiently than
either he or his wife, 36-year-old Janet,
could do.

"The marvellous thing about a com-
puter is that it has infinite patience.
Where anyone else might be bored with
a reading lesson after half an hour or so,
it will carry on until Sophie has had
enough; and when children are really
interested in something) they can go on
for hours.

"The computer also makes things
much more fun; learning becomes a
game. I have written two educational
programs for James and Rhian and they
love them. Yet if I showed them the
same facts in a book they would tell me
to get lost. Books do not tend to be
fun".

One of Denfs educational programs
is for learning tables, a tedious task for
most schoolchildren. Yet James and his

friend both worked their way through
the program during my visit with en-
dent enjoyment, not to mention great
accuracy.

The other program is on elementary
physics, an explanation of the differ-
ences between gases, solids and liquids.
A simple explanation of each is followed
by a simple question to test the child's
comprehension of what has just been
read. An incorrect answer takes the

child back to the relevant text, whk h
may be read again for a better under-
standing.

There are no pictures, no tunes-
only words. Yet the program has proved
popular with the children in a way no
physics text book could hope to do.

"If you want to know the answer in a
text book, you have to look it up each
time al the back of the book but here it
tells you immediately whether you are
correct. It also means you cannot cheat
or skip pages as you can do in a book. It
is programmed so that you cannot move
on until you have understood and an-
swered a question correctly on one par-
ticular section".

The Dent family does not use the
Spectrum only for serious programs.
They use many of the games programs
on the market, too, and Dent was forced
to admit that he is usually beaten by
James.

He sees the implications of the com
puter generally as far-reaching. Already
the health authority at Walsall, where
he works in a group practice, has a
computer which can recall children for
vaccinations more accurately than hu-
man labour could do.

There is also the potential for com-
puters to be used in many other forms
of recall in medicine, such as women
needing regular cervical smear tests.

Dent feels that if individual practices
could have their own computers they
could prove invaluable in assessing indi-
vidual practitioners* performances. He
has already written a Basic program as
an experiment for patient use. It as-
sumes that the patient is complaining of
a stomach pain and asks a scries of
relevant questions to which the patient
responds by pressing a key.

The computer assimilates the various
responses so that Dent can press
another key and be given one or several
possible diagnoses.

I was invited to try the program and,
being unable to remember the full de-
tails of any stomach pain I might have
had, caused a rather confusing diagnosis
which ranged from dyspepsia to gall
bladder trouble. The point was that it

124

SINCLAIR USER Annua! I9M

was fun and I think I would have
though) so even if I had a pain at the
time. It also seemed more private and 1
could take my time in pinpointing the
exact spot of the pain without worrying
thai the doctor might become impa-
tient.

The program is not something Dent
will use wilh his patients; it is simply a
test for himself at ihis stage.

*'I think a computer could become
very useful in this field. Certainly it
would save some time if a patient were
io answer the questions before going in
to see the doctor. It is a fact that a
doctor, being only human, cannot ask
the same questions without some form
of bias".

With a computers a patient is given
no hint of an expected answer, or the
possible element of surprise at any
given answer, but Dent is quick to point
out that the computer is not in itself
sufficient because it does not see the
patient.

"The computer cannot possibly no-
lice that the patient looks more tired
than the previous week, For example, or
seems to be depressed about something,
but it might have a function in produc-
ing, very quickly, a list of possible
diagnoses for a given complaint".

Dent, who lives with his family and
his Spectrum at 5treetly 3 near Sutton
Coldfield in the West Midlands, trained
as a doctor in London and has been

practising at Waisall for five years. One
or two of his friends in the area have
their own home computers but he says
his children know more computer own-
ers than he does.

"By and large, children seem to love
them. If they think a computer is Tun
and it helps them to learn, I cannot see
anything wrong. I certainly do not feel

'The computer also

makes things much

more fun; learning

becomes a game'

it is indoctrination or anything. When a
child becomes bored with the computer,
he has only to switch it off and walk
away".

Dent is hesitant about predicting the
success of a computer as a replacement
for school because of the social implica-
tions.

'*It is a good teacher but I think the
children would miss school friends,
football and so On. We hope that Sophie
might learn from the computer to read
and perhaps to write before she begins
school.

"If there were no school in the area
which seemed acceptable to us, I sup-
pose we might consider teaching her at
home but that is not the case and,

anyway, I think we would make that
decision with or wiihoui (he com-
puter".

At the moment the Spectrum is So-
phie's toy, one of many. She under-
stands that io press a key will produce
something entertaining on the screen.
She does not yet know that it can make a
difference which key you press and she
certainly does not understand that tapes
were not designed for unravelling with
a little finger and trailing across the
floor but given that she is still a baby,
her familiarity with computers should
make all those things far easier to learn
in the next few years.

Her seven-year-old sister already en-
joys entering programs, with a child's
unquestioning acceptance of the repet-
itive details required in instructing a
computer— and she started only six
months ago.

The Dent family has found a toy, a
teacher and a potential secretary all in
one. The next stop will be 10 buy an
interface to enable them to use the
Spectrum as a word processor.

With an age range spanning one-third
of a century, they have found something
from which each can benefit. As a
family they have been converted.

If Tm&r} would tike to nominate people for User
itf the Month, phase virile to Sinclair User, 1 96-200
Baili Pond Road, London Nl 4AQ f>tvwg name,
addren and daytime telephone number and the
reatonsfor (he nomination.

SINCLAIR USER Annua! 1984

11$

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PROGRAMMABLE

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or ZXS1

ABOLTOUR INTERFACE

I he AGt Programmable Joy slu'k Interface is
a unique design offering [he use of any AMri-
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The hardware programmable inter Luc re-
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replicate* the keys of the computer in a
manner which is responsive to absolutely
ALL key reveling methods, both BASIC and
Machine Code.

Trie interface does not interfere with key
operation and can therefore be used simul-
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There is no need to remove the interface once
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actormrjndjte further expansion, i.e primer*.
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The key replication principle pioneered by
At; h means that your own programs can use
eight directional joystick movement by
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Two joystick sockets are provided which
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majority of two player games. Several inter-
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I lie interface is programmed by a two dipii

code, which is looked up on a programming

chart supplied, for each direction and firing
hut Ion, The two numbers are I hen selected;
on « pair of leads which are clipped onto"
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Once configured this can be marked on a
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PACKAGE CONTENTS SUPPLIED

• Programmable Interface Module as [Uvf
trated, complete with clip-on program-
ming leads.

• Self adhesive programming chart detailing
how to define which key is tirnulaled hv
UP. DOWN, LEFT, RIGHT, and FIRE.
This can be fixed on to the cast of your
computer or if preferred rhe protective
backing can he left on. 1 lie < hurt p*. made
of a very durable reven* printed plant ic
and is extremely easy in read.

• One pack of ten Quick Reference Pro-
gramming Cards for alliance letting
to your games requirement*. I he card
allows you to mark the configuration in
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record the software title and company
name.

■ Video Graffiti demonstration program
which is writ ten totally in BASIC lu illus-
trate how all eighl directions and fire
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resolution drawing program.

• 12 month* guarantee and full written
iris true I ions.

JOYSTICKS

KEV FEATURES

* Programmable design gives TOTAL soft-
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* Accepts Alari, Competition Pro, Wico,
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* Hear extension connector for all other
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* t-'ree demo program and instructions.

I CONTROLLERS {

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FOR USE WITH OL'R INTERFACE
Module or VIC 20, Commodore 64,

Atari VCS, Atari 400, Atari 800

J I yew require exira Joystick*, for our

original interface module mark order

'OLD? Joyflicki

ONLY £7.54 inc VAT + P&P

FROM: MR/MRS/MISS

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SEND CW-0- (NO STAMP NEEDED! TO: A.G.F. HARDWARE, DEPT, 5A,

FREEPOST, BOGNOR REGIS, WEST SUSSEX, P022 9BR

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PROGRAMMABLE INTERFACE

33.95

JOYSTICK(S)

7.54

PACKJS) QUICK REFERENCE CARDS

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ZX61 D ZX SPECTRUM □ Please tick

FINAL TOTAL

DtAl.l ;

VtR (£S W£L ( OMt EX FOR T PR fC£S t>,\ -1 /'/'/ ICA Tl

■;■■-.

126

SINCLAIR L'SER Annual IW4

SPECTRUM & ZX 81
EDUCATIONAL SOFTWARE

CALPAC LEARNING SERIES

Uh mr Campum Arrive L-5".r.Hj FA<Cli» to help mw «rl»ldi«i> *nb iheir H:hai* irorl Hw
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VOLUME 1 [Ifom 6 years) "50

r»ni Jr« mm idAHois »•*» sufiirjcKKi Willi 6s\mml iwtfi t*cilnm; powflrrul. »»** •(■? "■« <lrm,irm

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VOLUME 3 (from 9 years] £9-50

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Wc have a demons! ration cassette available for mtilcn or schools

TAKE A BREAK
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Choose between various time based skill
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Ask us for a catalogue;

Sussex Software

FREEPOST : Devizes SN10 1BR

Wiltshire

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Ffjr ZXB1 £

Every computer needs

CHATTERBOX If

"Listen creep. I am ihe leader...

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BBC
TRS80
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Play 3- part music, sound eftecis. drums etc. Full
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Symhciifi^' Music

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claims i» victims
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rtcmorislraliorii Genefales
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Please add VAT at 1 5% lo prices.

Barclay Access orders accepted by telephone

All enquiries
S.A.E. please

WILLIAM
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SYSTEMS Ltd

Quarley Down House
Choldertor
Nr. Salisbury
Wiltshire SP4O0Z
Tel09B0&l235

SINCtJUR USER Annual 1984

!27

Taking the strain out of
calculating the wages

Starting with the ZX-80 Ronald Sims has always found serious uses
for his machines. Claudia Cooke talks to him about how they help.

NO-ONE was more pleased than
Vera Sims when her husband
Ronald invested in his first
computer, a ZX-80. For the first time in
almost 20 years, her workload was re-
duced from a day-and-a-half each week
to only four hours. Mrs Sims has the
job of calculating and paying the weekly
wages for the 35 employees of the fam-
ily automation business.

"I used to do ii all in my head, with
the help of a ready reckoner and it took
me a day and a half Now my husband
has written a program which does it all
for me and it takes a few hours. It has
been marvellous".

Her husband has since changed to a
ZX-8I with a 64K. Memopack and the
program covers job costing for up to 10
jobs, tax deductions, a variety of indi-
vidual allowances and more than 30
subtotals and totals.

Airs Sims, 69 ? says: "It was a bit
strange at first because I didn't know
the first thing about computers but I

soon got the hang of it and now I'm
really pretty quick".

Husband Ronald, 70, interrupts to
reveal that the early days were not that
simple, "She just wouldn't believe it at
first. When the computer produced the
figures she used to take them down

'The computer just

cannot make the kind

of human errors

everyone makes'

quickly and work it out herself to make
sure, I must say her calculations were as
quick as those of the computer.

"Now she realises that the computer
just cannot make the kind of human
errors which every person is bound to
make at some time or another".

Although the Sinclair is his first com-
puter, Sims is no newcomer to the
processes of logic involved- He had

worked in the radio industry since 1929
and had become fascinated by 'wire-
lesses' even before he left school at the
age of 17.

"At school we had a physics master
who was very keen on the wireless, as it
was known in those days. I was charged
with his enthusiasm and by the time 1
left I was one of few people who knew
how they worked."

His first job was with a firm selling
do-it-yourself wireless kits. People
would buy the kits on Friday, he says,
and return on Monday to find what
they were doing wrong. His job was to
advise customers exactly how to assem-
ble them.

"In the early 1930s I realised my
technical education was not keeping
pace with the changes so I got a job with
Siemens in telephone exchange devel-
opment work. The logic then was the
same as the logic of computers today
and 1 was given a good training".

When the second world war broke

128

SINCLAIR t 'Si-It Atutwt tSS4

out, the company had jus: begun work Christmas. We couldn't drag them
on the development of radar and Sims away from the set. We all enjoyed it",
became chief of test gear. The eldest grandson, aged 12, has

"There was such urgency because of already had the ZX-80 bequeathed to
the war that we had to start manufactur- him, together with the 16K memory,
ing in quantity products which had not
been made previously. Being respon-
sible for testing, it was the first time 1
really became interested in automation
and automatic testing,"

After the war, Sims left to join Mi-
chael Sobell, first as technical assistant
to the buyer and then as chief buyer. He
stayed with the company for 12 years
and says that without Sobell's commer-
cial guidance he could never have start-
ed his own business-
Start it he did, 25 years ago, when he
detected a gap in the industry for auto-
mation. Today his company, Lectromcc
Controls, is still flourishing in south
London, run by his three grown-up
sons and his 2X-81.

He is working on a cashflow program
for the firm, although he is doubtful
whether his Memopack can cope with a
sufficient number of invoices

His wages program took many
months to compile but the result has
been worthwhile. Not only does it do
the job much faster, it rules out the
necessity for Mrs Sims to have her cash
sheets checked by someone else before
handing-out the pay.

*'If you make a mistake you just look
at the picture and know if it's right or
wrong", says Mrs Sims. "The only
thing is that you lose your brain, be-
cause you just look at the picture and
copy it all down. I used to have to make
so many calculations in my head but
now 1 almost think you could become
brainless within a few years."

Sims has one criticism of Sinclair,
levelled at the printer. "I think it was
very ambitious to produce this printer
but I think il leaves a lot to be desired.
It prints so badly; 1 think it's the ther-
mal paper. If you leave it switched on

He is at least as enthusiastic as his
grandfather.

Now Sims is working on a conversa-
tion program to use with his grandsons
at this year's Christmas gathering. It is
a marvellous program so far, tailored
individually to each of the four boys so
that if one gives the computer his name,
it is liable to answer back with the name
of his brother.

A selection of 10 answers to each
response from the boys appears at ran-
dom, resulting in some highly-enter-
taining non wquiturs, as well as some
startlingly accurate replies.

When asked how I was feeling by the
computer, 1 replied "very hot", only to
be told rather cheekily: "You look all
right to me". When I agreed with the
computer's suggestion, "1 heaT they call
you Podge", it replied curtly. "Stop
mucking me about".

Sims hopes to develop the program to
around 10 or 15 minutes by Christmas
and is gaining evident enjoyment from

'I think it was very ambitious to produce the
printer but it leaves a lot to be desired; it
prints so badly. If you leave it switched on all
day the thing gets war m and the print blurs/

all day, which we might need to do
often, the whole thing gets warm and
the prim blurs".

On the whole, though, he sees his
computer as a great boon and not only
for work purposes, "We have four
grandsons and you should have seen
them With all those computer games at

the work involved.

Aside from the computer, he and his
wife are kept busy at their home in
Kwell, Surrey, Mrs Sims is a regular
bowls player, although sadly out of
action during my visit due to a back
injury. Her husband likes nothing bet-
ter than to sit down for an hour or so

and play the organ. He is from a musi-
cal family and as a child learned to play
a variety of instruments, including (he
piano, violin, flute and piccolo, but his
favourite remains the organ i particu-
larly love playing classical music. I have
always found it relaxing. To return
home and get lost in the music for a
time is a wonderful way of recovering
from work".

The Sims also have a narrow boat,
moored on the Thames, to which they
retreat whenever possible during the
summer months to enjoy the sun and
the fresh air.

"Mostly we take it on the Thames
these days, rather than the canals, but it
is a wonderful way of relaxing. You
don't have to arrange it all in advance;
you just decide to go and that's it. It's a
kind of freedom which is very valuable
in business because, contrary to popular
opinion, you cannot just take-off on
holiday overseas whenever it suits you.
You never know what will happen until
the last moment".

Both are now semi -retired and the
father figure wisely attempts to keep his
nose out of the family business to a
great extent, leaving his sons to run it
the way they wish to do.

"I never pushed them into it, or
expected too much of them. They all
worked for other firms for a few years
before joining me but I must admit it is
pleasant that they all wanted to join.
Now one is the managing director, one
is sales director and the third is really
installation manager".

One of his sons has also become a
highly-proficient organist, playing in a
dance band. His father pours generous
praise on his talent.

Married for 43 yeaFS, the Sims are a
contented couple, although not content
10 sit back and do nothing. Theirs is an
active life, made more so by the advent
in Their home of the computer.

They certainly defy any theory that
computers are for the young. It was Mrs
Sims who, having read Sinclair U$er s
became the first person to nominate
someone for the title of User of the
Month — her husbund.

She nominated him not only for his
wages program but also for the fact that
, he derives so much enjoyment and re-
laxation from compiling the programs.
His enjoyment of making the programs,
she says, is almost greater than his
enjoyment of operating them in his
computer and although she steers clear
of programming, she has learned a new
skill at an age when few women expect
to do so.

SINCLAIR L'SER Annual 1984

\29

N-#

SPECTR UM USERS

NOW AVAILABLE— THE ULTIMATE
IN GAMES ACCESSORIES

THE FOX PROGRAMMABLE INTERFACE

The Interface with:

Total compatibility with all games.

Proven compatibility with the Microdrive.

Built in memory to store up to 16 different game keytops.

Battery back up so no loss of memory after power off.

Trickle charge batteries used so they recharge whilst in

use (no replacement needed ).

Only one two-position switch for simplicity of use {no loose

wires or clips to attach).

Accepts any Atari type joystick.

Fully cased' with through port for further expansion.

Can be used as a pseudo ROM for personal tool kit.

Just plug in switch on and play the game with Fox only £28.50 incl

*
*

*

*

• SPECIAL CHRISTMAS OFFER *

Buy the Interface with the Quiekshoi Joystick or
the Triga Command Joystick (normally £12.50) for only

£37.50

INCL

ALSO AVAILABLE— THE FOX 48K
SPECTRUM UPGRADE

UPGRADE YOUR 16K to 48K

The kit reviewed as "Easiest to Fit" and "Best value for Money"

Simple insertion, no soldering required, full instructions and guaranteed.

Move on up to 48 K

only £20.99 INCL

°?$*

& 5 -

I

And at last the keyboard
with a space bar for
the Spectrum,
THE NEW FDS

This elegant desk
top system, designed
for the professional
user. In its slimline
case, the superior
keyboard contains all the
graphic characters for the above
computers. With the additional function
keys and SPACE-BAR, speedy and accurate data entry is made simple.
The Fuller FDS is easy to install, based on the very popular FD42
system, it requires no soldering or technical knowledge.

Sent I now to:

Fox llk-c ironies Lid.

141 Abbey Rctad. Basingstoke.

Hants RG21 9 ED

Tel' mSB 20671.

Please send me
Interface

| Interface with Quickshot/Trijja
^\ Upgrade
^J FDS Keyboard

Nome

Address ,

I enclose £

or please debit my Barclaycard

x°- ; l l i i f f f f ft

Callers welcome by

Appointment

no

SINCLAIR USER A«nuet I9»4

Memory

Expanding memory on both the basic ZX-81

and the 16K Spectrum is a major concern to

Sinclair owners. Stephen Adams reviewed

the expansions systems available for both

machines and the results are re-printed here.

S9 #4 SINCLAIR t.'SER /i»" U al 1984

m

Cheap is not nasty
in memory packs

Stephen Adams examines the many ways of
expanding the storage of the ZX-81.

THERE ARE so many ZX-81
RAM packs around these days
that it is worth looking at what
they can offer in the way of more
facilities.

First, a little explanation of the ZX-
SI memory map and ROM routines
would help in understanding the limita-
tions of the ZX-81.

Sinclair engineers, when they de-
signed the ZX-81, did not expect that
anyone would need more than J6K of
RAM. So they took some short cuts in
the design which made it cheaper and
easier to access the RAM and ROM.
One of the them was to restrict the
upper 32K of the memory map to work-
ing the screen and nothing else. The
other was that the ROM, which is only
8K longj was allowed to repeat itself
throughout the memory map unless the
RAM was working in that area.

Those decisions allowed them to de-
code only the top two ADDRESS
lines— AM/A 15— to determine whether
RAM/ROM or RAM with DISPLAY
was on at any one time, the address line
A15 deciding whether the display was
on or not and the display being on only
in the top 32K of memory and Thus
dividing the memory map in half,

The A 14 address line divided each
32K section into two quarters, the bot-
tom half of which was ROM and the
top half RAM. As they were the only
decoding done inside the ZX-81 the IK
of RAM repeated itself all the way
through the 16K. RAM section

Memory map ..>(' thr ZX-81
§4K

4BK

RAM for display — display fllr

32K

RUM appear* again

sac

IK or 1«K RAM

16K

IK or 1CK RAM

HE

ROM appears again

OK

True ROM area

When the 16K RAM pack is added,
ho wever, it is switched-offby the use of
the RAMCS line on the edge connector
and the RAM chips in the RAM pack
do all the extra decoding necessary to
divide the 16K section into individual
bytes.

To expand the memory above 16K
required some special decoding in the
RAM pack so that it did not interfere
with the display, which needs a repeat
of the first 16K of RAM at 4SK and
above in the memory map.

It also required that the ROM be
restricted to the first 8K of the memory
map. Th at was done by using the
ROMCS line in the same way as the
RAMCS was used on the t6K RAM
pack. xVtemotech was the first company
to produce a 56K RAM pack. Most of
them are now called 64K packs but you
can use only 56K and that allows you to
use 48 K for Basic and 8K RAM where
the ROM used to be, between 8K and
I6K, for machine code.

There are some restrictions on using
the 48K as you cannot run machine
code in it and you have to be careful
that the display file does not cross the
32K border. Memotech now has I6K
and 32K RAM packs in the same boxes
as its 64 K. ones, which are often used by
dealers as a second choice to the Sinclair
1GK RAM, Memotech has a good repu-
tation for service. The 32K pack allows
you to use your 16K RAM pack as well
to achieve 48K,

The boxes are made from extruded
aluminium and arc used as a heat sink
for the internal +5V regulator. RAM
wobble problems should be familiar to
all readers and Memotech is no excep-
tion but the company provides a Velcro
strip which binds the packs to the ZX-
81 and other packs. The instructions
are clear and concise in a hooklet accom-
panying each pack but they are expens-
ive.

The Sinclair 16K RAM pack has
received both complaints and p raise .
The complaints are from users who
have had to experience RAM pack wob-
ble, which occurs when using the Sin-

clair keyboard, The design of the RAM
pack is such that it is not connected
firmly to the ZX-81 and the top of the
RAM pack rests against the top of the
ZX-81 case. Every time the keyboard is
used that lifts the RAM pack from the
table and shakes it. The edge connector
eventually becomes so loose that anv
slight movement will disconnect it from
the ZX-81, corrupting the ZX-81 mem-
ory.

Several methods have been produced
to stop the wobble — flexible cables so
that the RAM pack can be laid flat on
the table from dK 1 ironies and the
RAM-LOK from Adapt Electronics
which bolts together the ZX-S1 and
RAM,

The best method, though, is to buy a
RAM pack which has been designed to
eliminate the wobble. They consist
mostly of not allowing the circuir hoard
to be connected to the casing of the
RAM pack, so thai the board can move
up and down inside the case with the
movement of the ZX-81. A reliable tttfl
edge connector is also required. Some,
like that from Cheetah, have also been
designed to wrap round the back of the
ZX-81 so that there is little movement
between the two casings. Some manu-
facturers are also using + 5V-only
RAMs so that they do not have to
provide a power supply from the +9V
supply which can vary depending on
the equipment used.

KLayde, Camel and Econotech 16R
RAMs are good examples of the first
type, the first two being cased. The ZX-
Panda and the Cheetah are good exam-
ples of the second type.

The ZX- Panda can also be used to
give 32K by adding a small PCB con-
taining I6K more RAM inside the case.
The Audio Computers RAM jut k pro-
vides a fairly stable 16K RAM pack
which has a hook to hold it on to the

112

SINCLAIR USJiR Annual 1984

back of the ZX81 and can be fitted with
an XROM pack which makes it even
more useful as it provides EPROM
loading and saving facilities. Some of
the RAM packs provide a LED — a
tittle red light — but that only provides
an indication that there is power to the
RAM pack and not whether it is work-
ing correctly.

The best choice is obviously a non-
wobble RAM pack which is inexpen-
sive. If you can afford it and do not
want to use pre-programmed ROMs or
other devices, opt for a cheap 64K
RAM pack. They take up just as much
power as the 16K and will also work
with the Sinclair printer — see the table
for a list of facilities of the various RAM
packs.

Basicare provides a different kind of
RAM;; you must first buy a base module
to use its RAM 3 called a Persona. It is in
16K and 64K. packs for the ZX-81 up to
a maximum of 512K. That is divided
into banks and you will require other
modules to have the banks talk to each
other. The maximum memory available
at one time is 32 K. It is the only system
which allows you to run big programs
but at the moment there is very little
software to run it.

Yet another type of RAM pack is
available and that is the battery-backed
RAM — DROM, which allows the user
to do things which normally would have
to be run in from tape — instantly.
They can provide storage for routines to
side-scroll the screen in any direction,
assemblers, new operating systems to
replace the Sinclair ROM or even your
own favour lie Basic program.

A multitude of DROM packs is pro-
duced by Camel Products. Two of them
work on the ZX-81, the Memic 81 and
the Cramic The Memic 81 contains
one or two static 2K by one- byte chips
giving 2K or 4K of RAM backed-up by

a battery when the power is off to
preserve its memory. That occupies any
position in 8K-1GK area of the memory
map. DROM devices allow you to write
a machine code or a Basic program and
transfer it into the 8K-16K area of the
memory map. Machine code can be run
from there, saving valuable RAM space,
but Basic programs must be uploaded to
the Basic area before running the pro-
gram.

That means that any Basic program
is limited to SK unless the Cramic is
used which is 16K long. The routines
for the transfers are included in the
notes with every pack and consist of
machine code routines which must be
run by using the USR command.

The Cramic is a special case as the
16K can be switched in or out by a
software switch and so a Basic program
can be loaded from tape into the Cramic
and seal ed-ofF from the ZX-81. Power*
ing-olTtbe ZX-81 then has no effect, as
the RAM module has its own battery to
keep it operating. The program can be
restored by powering-up the ZX-81 and
running a machine code program to
step back in the Cramic where you
ceased. That leads to my first criticism
of the notes; nowhere is it mentioned
that you should save the machine code
program on tape, in case something
goes wrong.

The code required is very short but as
it needs to be put into memory before
using Cramic it would have been better

to load it from tape. That routine could
be stored in the Memic 81, of course,
which is outside the Basic area and the
routine loaded into the Basic area from
there. The advantage of DROM over
ROM is that it can be changed.

The other DROM is available only in
kit from from Hunter Electronics and
consists of board which plugs into the
back of the ZX-81 and provides 2K of
battery-backed RAM, with space for
three more chips. If you wish, some of
them can be turned into ROM sockets
to take 2K or 4K EPROMs,

The RAM pack race has now become
so cut-throat that a few firms which
were doubtful have withdrawn. The
firms remaining are giving the custom-
ers what they want, depending on price.
Cheap is not necessiirilv nasty any
more. So look for the bargains — they
are there to be found,

DROMS

Memic 81 4K #4,45

Cramic 16K £»!.«

Basicare 2 K £39.50

Hunter 2K £19.95

SUPPLIERS

Basicare Microsystems Ltd, 12 RicketT
Street, London SW6

Cambridge Microelectronics- (Camel). 1 Mil-
ton Road, Cambridge.

Cheetah Marketing Lid. 359 The Stfand,
London WC5 ,

JRS (Econotech). 19 Wayside Avenue, Wor
thing, Sussex,

dK Ironies. Unit 2, Shire Hit! Ind- Estate.
Saffron Walderv, Essex.
Audio Computers tSolldisk Ltd), B7 Bourne-
mouth Park Road, Southend-on-Sea, Essex,

RAM pack

A nti- wobble

+ 5V only

Cased

1 nee

Basicare lfcK

n*

**

£23,73

Basicare 64K

**

**

£76.23

Camel 16K

r'

**■

►"

£20, t4

Camel 64K

v*

**•

£80,45

Cheetah lfK

V*

V

£19.75

Cheetah UK

**

**

£44.75

Econotrch 16K

r*

£20.95

JK' Cronies I6K

V

V

£22.95

dK'lmnic* 64 K

iS

•s

£52.95

Audio Computers

V

r

J>-

£1»,&5

Memo tech ISK

V

£20,»

Mcmnttch 32 K

**

fitJt

rVtemoteeh 64 K

V*

r*

iw-tfl

Sinclair I6K

**

£29.95

ZX -Panda

V

**

•S

£19.35

SINC1- AIR USER Annual 1984

I U

Upgrade your

16K
ZX SPECTRUM

Now!

The CHEETAH 32K RAMPACK simply plugs into the user port at the rear of
your computer and increases the memory instantly to 48K

* Fully compatible with all accessories via rear edge connector

* No need to open computer and invalidate guarantee

* Why send your computer away and wait weeks for upgrade
+ Fully cased tested and guaranteed.

Why wait any longer?

Only £39.95 including VAT and P&P.

Now make your
Spectrum and ZX-81 Talk

The Cheetah ,J SWEET TALKER" just plugs into the back of the computer using the existing power supply. Based on an
allophane system you can easily program any word sentence or phrase, fully cased, tested guaranteed and compatible
with all accessories via rear edge connector, Complete with demonstration cassette and fufl instructions, No more lonely
nights! Simply incredible at £29.75 (Please quote when ordering whether Spectrum or ZX81 owner!

16K RAM Pack for ZX-81 £19.75

64K RAM Pack for ZX 81 £44,75

Prices include VAT r postage & packing. Delivery normally 14 days. Export Orders at no extra cost, Dealer enquiries
welcome.

Send cheque.'PO now to:

CHEETAH MARKETING LTD
Dept SA
24 Ray Street
London EC1 R3 DJ
Tel: 01 278 6954
32K RAM Pack and 'SWEET TALKER also available from larger Branches of

John Menzies

WH SMITH

1 M StNU JUR USER Annual 1984

Sinclair has been overtaken by other suppliers
of upgrades, Stephen Adams reports.

Spectrum
finds itself
at full stretch

THE SPKCTRl'M is in four ha-
sie forms. Model Is which have
two IC-type sockets into which
a printed circuit board is plugged and
model 2s which have all the RAM fitted
on to the main printed circuit board.
There are, of course, two types in each
category, the 48K and the I6K..

The 48 K cannot he expanded, as all
the existing memory space is covered
with either ROM or RAM - all 64K d
it. The ROM can be switched-out exter-
nally to add different ROMs using the
ROMCS but the RAM cannot as there
l^ no equivalen: RAMCS,

Therefore ah memory expansions can
he done only to the I6K models. As the
computer already contains IGK of
RAM, the top 32 K of memory area —
32K-64K. — is the only space to put it.
Most memory expansions fit] that space
with 32K. worth of RAM chips but the
East London Robotics 64 K add-on —
the SP80 - has two sets of UK RAM
which can be switched in and out under
a program instruction or from the key-
board.

The kits consist of four memory
decoding chips, except model 1 versions
where all the chips are soldered to a
PCB, and eight 32K by one-bit chips,
Those RAM chips are very sensitive to
static electricity and warnings are in-
cluded in all the instruction sheets. The
way to handle them properly is nor to
remove them from their protective
packaging until needed and to keep
touching an earthed object such as a
radiator or gas pipe occasionally 10 re-
lease the static charge. The static can be
caused by nylon or wool in your cloth-
ing being rubbed.

Putling-in the chips can be a little
difficult and it is recommended thur
check that the pins are straight before
vou insert them. The Fox Electronics
kit has the pins already straightened.

Also check that none of the pins is bent
outside the socket or underneath the
chip when vou have finished.

The best technique to use is So put all
i lit pins on one side into the socket and
then to pull the pins on the othet side
over the holes m the other side ol the
socket. Once both seis of pins are rest-
ing in the socket holes vou can push
(town gently on the chip to push it into
its socket.

The instructions vary from a four-
page, step-hy-srep meticulous descrip-
tion by Delta Research to one page jusl
listing where the chips go by Fuller.
Apart Irom the Fuller instructions all
provided sufficient detail to allow you
to know where each chip goes and what
precautions to take

As part of its instructions Fox Elec-
t tonics also includes a sheet showing
how to tune the colour on a Spectrum to
give better results. It also shows you
how to tell whether it is the Spectrum
or the TV set causing a problem. Sheets

'The 48K
cannot be
expanded'

normally com £1 from Fountain Elec-
tronics but are free with its RAM kit 5
along with a small Basic program to
demonstrate the usefulness of 48K.

The fitting of the Fox kit was the
easiest but if you have problems you can
send back the kit with the details of the
Spectrum at any time in the following
12 months. East London Robotics will
fit the chips at an extra cost of £7 by
post or £3 by personal visit.

Delta sends a memory test tape which
checks all the memory by using a ma-
chine code program going through at

least all the manufacturer's specifica-
tions, The mpe can be used to keep an
eve on suspect memory faults as it
with an error which can then be sent
back to Delia Of Sinclair. The tape
normally would cost £3.50 and is j
jl'.iLK comprehensive test taking at least
eight minutes.

Lis: London RobotlCf and Delta
were I he only model I boards we could
test and both could be fitted easilv with
less trouble lhati the model 2.

I '"ast London Robotics .ilso docs an
SP.HO kn which can provide (S-lR ol
memory in the same sockeis as the SP 18
{-ISRi lined. Thai is achieved by having
i wo separate banks of 32 K* switched by
an OUT instruction.

Thai is possible only because of the
64 K RAM chips which are used instead
of the '>2K RAMs and a massive modifi-
cation of the decoding chip 1 * which pi ii"
into i lie Spectrum, No soldering is re*
quired bul some care needs io be taken
inserting the chips, as three ol them are
wired together using twisted insulated
wire.

A LED is also soldered on to one oJ
the chips to indicate which bank is
being used. The only problem is that
you can sec if only with the top oil" or
looking through the edge-connet for
hole The LED hghis when it is in bank
two and when the machine is turned on
the light shows on bank one.

The only problem with the SPfiO is
that the stack and any program running
in it must be in the IftK of memory
provided by Sinclair. If it was allowed
to go into the top ?2K u would be
switched-out on the lirst OUT instruc-
tion and the program would have no-
where to go.

Also the machine code stack for re-
turn addresses would have to be in the
lower IfiK area for the same reason.
That leaves the user to develop a pro-

SINCLAIR USER Amtmt 1984

135

1

gram which will be able to use banks of
memory without having the conve-
nience of Sinclair Basic to cope with it.

Prices of the various kits are detailed,
along with an indication or how good
the instructions were, guarantee period
and number of tests performed on mem-
ory after fitting.

It is also possible to add a. RAM pack
on the back of the Spectrum. A Spec-
trum-type 32K RAM pack has been
produced by Cheetah Marketing Ltd. It
fits very snugly on the back of the
Spectrum and because it is outside the
case it does not matter if it is model 1 or
model 2.

It also has an extension piece on the
back so that you can plug in Micro-
drives when they arrive. The RAM
pack has no known wobble in use and
can bjc fitted very easily by plugging it
into the expansion port. It costs £39.95.

The alternative is to use a ZX-81-
type RAM pack with an adaptor to give
you another 16K or 32K. To use it you
will require an adaptor,

KPROM Services and myself both
make adaptors for the 16K. RAM pack.
Mine can also cope with a 64 K RAM
pack to give a full 32K by changing a
soldered strap on the board or ordering
a 64K version, 1 also produce an Adam
I] which lets vou have a 16K RAM

pack on the back of the Spectrum but
which also allows devices which used to
work in the popular 8K-16K region to
work in the 56-64K region of the Spec-
trum. All the adaptors mentioned cost

Of the RAM pacKS and kits reviewed.
Fox Electronics for kits and Cheetah for.
RAM packs stand out as good value for
money.

Fok Electronics, 141 Abbey Road, Basing-
stoke, Hampshire Tel: 0256-20671

Cheetah Marketing. 359 The Strand. Lon
don WC2 OHS To!: 01-240-7939.

East London Robotics. No. 11 Gate, Royal
Albert Docks. London £16- Tel: 01-471
3308.

Delta Research - cheques to Servodata Ltd
- 15 Church Street, Basingstoke. Hamp-
shire. Tel: 0635 46373.

Fuller Micro Systems, 71 Dale Street, Liver-
pool 2,

Eprom Service's. 3 Wodgewood Drive, Leeds
LSB 1EF. Tel: 0532 667183

Stephen Adams, 1 Leswin Road, London
N16 7NL,

Producer
Fox

ELR

Delta

Dclti

huller
II K
ELR

KAM

12K
32K
32K
32 K
32K
UK
64K
64K

riislrutluMi-.

Good
Good

V. f^iini
V. good

I J oor

Average
Average
Average

Model

Guarantee

Tan

Price

2

12 mom hi

1

£24

2

1

£23.65

I

>100

£3*

2

>IO0

£26

2

i

£24.30

2

i

£2V6'i

1

i

0a

2

i

£46.65

A world of activity for you
and your Sinclair

Whether you have a ZX80, ZX81 or Spectrum - we can show you

O there's far more to your Sinclair than you ever thought possible.

That's the active, lively world of Sinclair User — the first magazine

written specially for everyone who owns or uses a Sinclair

computer .

Every month, there is a whole range of games, business ideas and

bright new ways to learn. There is the Sinclair User Club, with

special exclusive member offers. There are technical facts,

development news and advice, plus hints from other users and

answers to queries — in fact everything you need to be an

interested, informed and ACTIVE Sinclair user.

There's iu&t one problem — Sinclair Use* sells out fast! So make

sure you don't miss your copy: order it today from your

newsagent — or complete the subscription

form below and we will _ *•

send it to you direct, every month. ^ -** "~vjs£** e

to

-*--^ ^ves _„ lot *■

t,o s

1»

&tM

136

S1NCLAIK I'SI'R Annual 19B4

Thoughtful Presents

Buy fhe latest in educational toys for Christmas
— educational software, LCL has learning
games and useful courses, for the Spectrum,
ZX-81. BBC, VIC, Electron, Apple and PEL for

example:

MICRO MATHS. 24 program self-tuition or revision
course to O-Level. £24.50 (except ZX-81 £14.50).

ANIMATED ARITHMETIC. Teaches using moving

colour pictures (not words), includes Clown
Count and Addition Express £6.50.

" . . the programming standard is high. The
programs are robust . , ."

TIMES EDUCATIONAL SUPPLEMENT

RETURN-OF-POST service for Micro Maths, Phone
or send orders or requests for free catalogue to:

LCL

26 A von dale Avenue,

Staines, Middlesex,

Tel: 0784 58771 GENEROUS TRADE DISCOUNTS

m

World leaders in Maths educational software
[Distributors in 24 countries].

New acton sports QamS* Usalurea 3D view ot true floma In (oottsalF anal tennis

you play one side the compile* plays 1*ie other Thus comput W It fott ond ha«J

10 beat fjtfleront LkilF levels

FOOTBALL

facti player can move, shoot etc ifjoapenosnMy Includes louft II players.

eofilde. COfrws.. Ihrow-ms sfc Scale 90, minules play Any learn or names Can

t& mod. Game can ba sisfjended and play* numb#fi ihowfi a' tile, press of

a key Pile* t5 SO

BKi HATCH SOCCER

just like fooltrall game but lot 2 p*ayers Eoetl plover irtes <eys 01 Mss s«Je of tiie.

i^yboard lo cofllroi his m#n. All men can ba moved. s*ioot etc rnoep«rvde.r*tly

Prochca vntti footoaK theft play your friends in the dig mnPch Wet £9-50.

smsoccEt

A detyste version of 1he tootball IEv»n roller acllon, Harder to fceat Choose
'.-.i - ■,•■: • .". n- P'ice e; orj

ItNNlS

Eojcn key ofays a difle»eril sriokfc Move your players anywhere on ogurr

Coni(Xjr*f ptoyj O hard rjame All tennis rules used, iusi like the reai tNno.

Proper serving and scoring Plays 3 tets Animated figures PRICE £550

TAJ* BATHE

30 view from trie lanfcs' turret of woods, * ilk>p*J. attacking lonki etc Shi

destroy Dui'tOinffi. Ireas and enemy tanks. 36D degree lurret movement Prtce

14.50

CASCACt

you *iva one car. the computer the 6ffi« Conlrol VOW car with steering ana

brakes Choice Of ? circuits Lop counter ana time recorded Price 13 95

Buy any 3 gam**, gel any gam* lr*e

■ ii ■ US KA3 ' - i vs." , .1- ■ .' r ■ a ^ ■'■ .^ r h " ■•.!'■

Winters Lid, Dept SUA, 24 Swanninglon Close Contk?y.
Doncasler, S Yorkshire, DN4 oUA

e keyboard
with a Custom
Keypanel Kit.

Everything you need
I S « m the keyb< iard \\ it h
(l STOMkfYI'VM L\

These precision die. -tut plastic panels fit perfectly

over your keyboard and provide an instant ami
individual reference to .til of your software

Each Kit comes in a clear plastic storage wallet and
contains: H) Matt-blackfCcypanels plus sheets
containing over 140 self adhesive t innmand labels
pre -printed with words, symlx il.s and arn t\\>, plus a
sheet ofblanks for your c iwn designs

SPECTRIM KEYPANKI.S are 96 x 2 2 i mm and the
labels ate printed in Spectrum" brighl red, \ Ml 1ST
for flight simulation and all multi-key games and
applications.

The PERST add-on for your Spectrum

< )RK; Kl;YPANI;;LSare* 10 5x2^ 5mm and the labels
are '( )Rf C blue. Master those ( ; YRl. and fS( ke\
combinations.

An 1 NSTANT reference to all ORlCs kevt* >ard
functions.

NOW IN SI JPER ML' PLASTIC!

hisi today m Sofu-ach Limited ^ CoUegC Hi Mil, KenUin>;,,
]k.-rkshire. K< rd Itjf' w^ ,h^-,,ii.tii,n.iuiirsui.i-.^p„iiyiri-!iiiii

l*k df*: send me:

Mpcetrum Ke>panel KiLsati.S.yS + SSpp&pciieh

(frtiTseas shiHik) iitJU iS't, Utr additional snrfaee mail)

«)R[< : K^parul Kii% :ii i I 9S + ^^p p& p «K Ii
(overseas ^hmild add 25% fi>r additiutial surhtx mail )

I t-neloseatotal remiuaneeotX (.iR-qucVpo^al

i irdt rs pavahk- lit Softest Ii MniiiedL

NAMti ,

f \l>l>RESS ,

L

_LI

SI KCI AI R t ! St R ^ rt nit j^ r «W4

137

f s 9ft

swaAM
1 2SS

COMPUT I NG

HIGH-RES ZX81 PROGRAMS

VYa uirlna a 5DF TVYAftL ONVi lachmqua to product ■ HIGH RESOLUTION DISPLAY

on tha UNMODIFIED 16K ZXH1 NO HARDWARE ADDONS AHE HFQUIflfO for
lha following pron r anta

INVAOfft! — raviawad •ciUlklll) in 'ZK Computing/ — " lh» Hi-raa djiplay
t* 96 iHllydnibltlkciwiirgunil ■mictlHin (imi.in Dutilmdina

acriia.amant . Aiwill'i ih» H i- r*l dupliy tha facilitiaa Offarad
iii impraaiiva' , Action ip tmonatti and fail iod, and tha aHplnalon
whan hit r a ally i* thaltatiiTj I" — *laad wa nv mm* 11
GRAPHICS — anabla* vo „ tou» high raidution grlphni in »nur own proorami
f|.» Tha cemmanda ara CLS- Pfll*JT PI PT. PflKS, DRAW, SPfllTI and

SCRtENOFF CnmprahanaiT* adilmg f acililiaa ara providad and
lha G-iphim command! ir* a'KIy 'ncrj-rparatad into BA9PC pratr'ama
—an aavancad ficidi flama i ncorper* 1 1 rty liva rj.tfaranl inaala- —
INVAOfflS. SAlftXiAraS, IDRFkANS. MtTEOrl STOMM A htOTHERSHIP
■rograiaiva difficulty < nd "i* »<■"• option*

—a fiat monlnu imidi lyp- !■«• Shoot dawn th« lluuri «•
that d*'l acipaa tha acraan li«n B than miajrlei. Prnpraaaiv* #" leu ltd",
NEW iOW PRICE. !
C»Vt GHUSAOL -IMi ■■ a tail fln*~.n. a gimi in which lha playar Mllll «i«|n
r2 95 Irani a cava purauad by ill farocioua inhabitant! TMl Santa dMl

n«ii nil h.g+i faiolutiDn gnphiti bui tha normal graphic* ara uaad
to goad aflacl. NEW LOW PRICL !

FOR THE 48K SPECTRUM

SPECTRAL ZQHF — limilat in iur ZXS1 pmgTim but uung colour *n# pound.
£4 S5 Thu la in-lad !■»« gimn in ona ■■ lha planar can chouint IS play

dui ihaal coniinuouiH if lodaairad. NEW LOW PRICE ■
CHILD'S PtAV — daaignad n a loathing aid for pra ichrjnl i;hildran with lha
fa 95 participation eta (inifli di tnchir Eicallant unmidi of Tha

Spicl'um'l colour graphic* miKtl 1hi» »ri anjnyabl* program Huh

NEW LOW PRICE >

SPECIAL OFFER

ftuy im ip mD»r firnrjiAfni In idiicr^urvi ot £ 1 par pjygrim HI

yy, j,a cnniiinllf loplHnp lor quality Spactrum infiwin for which w* pay
upt4 31% ruyklt-ioo- If yiru Klvi wriftin luch * prngi- am than land mmpll
tn ua l&r *" Jmmadial* Hiluanon Wa nrr/ alio aalaaMWd in program*
wniian gung r>ur GRAPHICS program for lha Z*B.

Trfdi anqui-rei ata walcoma

OOVSSEt COM PI/TING, 28 BINGHAM ROAD. 5Hem«rEJ£rp, NOT TINQHAM MOSSEP

Centronics Interface

Use v our Spectrum with a full-size printer

* Microdrive compatible.

* Double size graphics screen copy
with the Star and Epson printers.

* Produces colour screen dump with
the Tandy CDP 115 printer.

* Supports a wide range of software
including Tasword. Masterfile,
Omnicalc, Invoicing etc.

* Uses the Spectrum graphic characters
to control printer codes.

* Enables you to connect 2 Spectrums
to 1 printer.

Supplied complete with
Software and cable

£45.00

inc. VAT and Posting.

TRANSFORM LTD.

41 Keats Ho For Chester Mead Beckenham Kent

Tel: 01-658 6350

Z-8

CMOS STORAGE/MEMORY

WITH

BATTERY BACK UP

FOR ZX 81 IK or 1GK

* Fast Load, Save and Delete *

# Stores up to 10 Programs +
(6K total) for instant recall

* Software in Onboard Eprorn *

* Switchable 'Write Protect" +

* Alternative use as extra memory *
* Plug-in with connector for Ram Pack *

Inc. Price £44.90

With full instruction*

MICRO Z LTD

PO Box 83, Exeter

Devon EX4 7AF

S.AF. for full details

Advertisement Index

ACif Hardware 1 25

BttftottW SofTware 84

Bridge Software 121

Bu^-bytFj - 14.0

CCS 94

•:." , it I : .1- Computer' Software 127

Camell Soli warn Ltd 4. S

I :.i-:: .i:h' ii.ifi'"-; .... - ... /&

Chiaetari Markt-iiiKi .134

ComputHf kick , 38

f : r y ftt al Computing 2. 44

Dean electronics, 38

Dcric Compula* Services

I ,i-.r London Robotics 37

Famasy 'SofiTvare 139

Fox Electronics 130

Fuller Micro Systems H

Grill in & George

HartlarKt Software 113

Heatacre&l Lid IT :'+

H-ornhy Software 120

ISF 62

Jtlea ElactrofricE 1 13

Kelwood Computer Cases . fc>

Kemp Lrd ...12D

Kernow Soltwar* Services H3

Ktrsmos Software /•'

13?

Load RunnFM 115

Megadodo Soh ware 120

Micro I LI <t 138

Micro MoslBT 36

Microsp+iera

M ik i o Gen

Mymnttrjri SdllABr*

McAtoy, BS

National Entfrnsion CoBeQe

Nent Compulor Systems ,. ,

Odyssey Computing

Pan Books

Richard Shepherd SolXw«r4 H

Rose Software

Silvers-oFt Lttl

Softeaeh Ltd „

Stellar Software

Suisa * Top*S

Terminal SoftwHrrj

Transform Ltd , ,.,

Tteatop Designs

Ultimate Play The Game IS

Visions iSoltwaru Factory] Lid H)

Widgit Software

William Stuart Sy stems

Winters Ltd

91

B4

.72

44

3S

138

..84

, 67

44

109

137

121

127

..21

I3S

121

. 17

. 71
120

1M

SINCLAIR USfcR Annual 1984

I

I

The battle could be yours . . . . .
..... but it won't be easy!

PARTICIPATION - that is the name of OUR game. All our software contains a unique score verification
mechanism a/towing us to add a new dimension to computer games, Every Juiy and January we will be
publishing a ranking fist of the top 1000 scorers in each game with the overaff top 100 'grand masters' each
receiving certificates of merit bearing their position.

September is the last month to qualify for the Slack Hole championship. However, from October the
sender of the highest valid score each month will win software of their own choice to the value of £50,

Totally original game plan Addictive. ^° u &re took/

c0 \o^^ challenging and offering a complete ^Pyouuj

ge^y . visual experience with its animated your hair q u

ifccS- \ graphics and vfolent explosive effects. Pickery, f^ er

(1 ie Compatible with ALL leading joysticks, r 1 ' 5 Q&me

ye ^ J - A

X

1

SPECTRUM I

1* ■ 1

1

IV •

1 ■ 1

Up

^^ '

•

your hair qu

****** ther
Kagame

^^ysteryor-

"t causp i

SOFTTAi

:vs;

evg&

FANTASY SOFTW™,
is available from WKSmf.
John Menzies and
Computers For All

wt

v>*

■*»

SOFT WAFIE BY QUEST

SOFTVkn

iGBYn

*NT4s y

a me to re

Ail games are obtainable at £5

f m yen i i\_ j nit. uuuui iciuit. en j_j,

NTASY SOFTWARE, FAUCONBERG LODGE, 27A ST GEORGE,
despatched by return first class post together with a membersr

on our forthcoming blockbusting software.

Trade Enquiries welcome - telephone 0242-5

_

* ii mL •<T[ ^^

p*PFt^

Spectral

Sam

ZX SPECTRUM

mwm

>

&WS

^g^j^B j^Swr

ZX SPECTRUM

Av?5CT|

EDITOR, ASSEMBLER

KWTHE

j4

Wi

IX j« Cf MJA

iii

m*u

P

■ ^i

^ ^'zxiPtciftuM

-I'>^4^

^■^^^

t

BB

lATTHEW THOMAS on 051 -709 7071

wsT 1 "

Mulberry House, banning Place, Liverpool LI 8JB.

.->■